Answer:
16unitsStep-by-step explanation:
Given the length of the base of a square based pyramid as 12 units and the vertical height of the pyramid to be 15units, the height of one of its triangular faces can be gotten by using the pythagoras theorem.
Let the height of one of the triangular sides be s (it is also the slant height of the pyramid)
The vertical height of the pyramid to be h = 15units
The base of the right angled trangle will be half of the length of the base = 12/2 r = 6 units
According to the pythagoras theorem; s² = h² + r²
Substituting the given values into the formula we will have;
s² = 15² + 6²
s² = 225 + 36
s = 261
s = 16.16 units
s ≈ 16units (to the nearest tenth)
Hence the length of the height of one of the triangular faces is 16units
Answer:
16.2 units
Step-by-step explanation:
This composite figure is made of two identical pyramids attached at their bases. Each pyramid has a height of 2 units. 2 identical pyramids with rectangular bases are connected at their base. The height of the pyramid is 2. The lengths of the sides of the rectangle are 5 and 0.25 units. Which expression represents the volume, in cubic units, of the composite figure? One-half (One-third (5) (0.25) (2) ) One-half (One-third (5) (0.25) (4) ) 2(One-third (5) (0.25) (2) ) 2(One-third (5) (0.25) (4) )
Answer:
The total volume of the solid is 1.67 cubic units.
Step-by-step explanation:
Each pyramid with a height of 2 units and a rectangular base with dimensions of 5 units × 0.25 units.
1/3 x (area of base) x height
= 1/3 x (5 x 0.25) x 2= 0.833
Therefore, the volume of each pyramid will be
= cubic units.
So, the total volume of the solid is (2 × 0.833) = 1.67 cubic units. (Answer)
Hope it helped ya!
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Tysmm
The total volume of the solid is 1.67 unit³.
What is Volume?Each thing in three dimensions takes up some space. The volume of this area is what is being measured. The space occupied within an object's borders in three dimensions is referred to as its volume. It is sometimes referred to as the object's capacity.
Given:
Each pyramid has a height of 2 units.
and the rectangular base with dimensions of 5 units × 0.25 units.
So, the Volume of each Pyramid is
= 1/3 x (area of base) x height
= 1/3 x (5 x 0.25) x 2
= 0.833
and, the total volume of the solid
= (2 × 0.833)
= 1.67 cubic units.
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what do anthropologist study and why
Answer:
Anthropologists study human societies and cultures and the development of them from the past and present. They study this to analyze the differences and evolutions that us as humans have.
Musah stands at the center of a rectangular field.He takes 50 steps north,then 25 steps West and finally 50 on a bearing of 315°. Sketch Musah's movement How far west is Musah's final point from the center? How far north is Musah's final point from the center?
Answer:
The distance of Musah's final point from the center in the west direction is 60.355 steps
The distance of Musah's final point from the center in the north direction is 85.355 steps
Step-by-step explanation:
Given that :
Musah stands at the center of a rectangular field.
He takes 50 steps north, then 25 steps West and finally 50 on a bearing of 315°.
The sketch for Musah's movement is seen in the attached file below.
How far west is Musah's final point from the centre?
In order to determine how far west is Musah's,
Let d be the distance of how far west;
Then d = BC + CD cos θ
In the North West direction,
cos θ = cos 45°
d = 25 + 50( cos 45°)
d = 25 + 50([tex]\dfrac{1}{\sqrt{2}}[/tex] )
d = 25 + 50( 0.7071)
d =25 + 35.355
d = 60.355 steps
How far north is Musah's final point from the center?
Let d₁ be the distance of how far North;
Then d₁ = AB + CD sin θ
d₁ = 50 + 50 sin 45°
d₁ = 50 + 50([tex]\dfrac{1}{\sqrt{2}}[/tex] )
d₁ = 50 + 50( 0.7071)
d₁ = 50 + 35.355
d₁ = 85.355 steps
How many significant figures does each value contain? 5.6803 kg has significant figures. 0.00047 seconds has significant figures. 0.240 miles has significant figures.
Answer:
5.6803 has five significant figures.
0.00047 has two significant figures.
0.240 has three significant figures.
What are Significant Figures?Significant figures are numbers that are necessary to express a true value.
Place the values in scientific notation.
[tex]5.6803 * 10^{0} = 5.6803\\\\4.7 * 10^{-4} = 0.00047\\\\2.4 * 10^{-1}=0.240[/tex]
Explanation5.6803
The zero that is within 5.6803 is "trapped," meaning it is in between two nonzero digits. Therefore, all five digits are significant figures.
This answer is also already in scientific notation because 5.6803 satisfies the inequality [tex]1 < x < 10[/tex], which decides if a number is correctly written in scientific notation or not.
0.00047
The zeroes that precede the 4 and the 7 are not significant because they are dropped in scientific notation and are not trapped by other nonzero digits. Therefore, only two digits of this value are significant.
0.240
Since the zero at the end of 0.240 is a trailing zero, it is significant along with the 2 and the 4. The zero that precedes these digits and the decimal point is not significant. Therefore, only three digits of this value are significant.
Therefore:
5.6803 has five significant figures.
0.00047 has two significant figures.
0.240 has three significant figures.
1/3(12-6x)=4-2x I need help pls
Answer:
no solution
Step-by-step explanation:
1/3(12-6x)=4-2x
4-1.3x=4-2x
4=4-0.7x
0=0.7x
ns
in triangle ABC A-B= 15 degree, B-C= 30 degree find A,B,C
Answer:
A=80 , B=65, C=35
Step-by-step explanation:
A-B=15 ⇒A=B+15
B-C=30⇒-C=30-B ⇒C=B-30
the sum of angle of a triangle = 180
A+B+C=180 ( substitute A and C)
B+15+B+B-30=180
3B-15=180
3B=180+15
B=195/3=65
C=B-30 ⇒ C=65-30=35
A=B+15=65+15=80
check : A+B+C=180
80+65+35=180 ( correct)
The length and width of a book cover are 22.2 centimeters and 12 centimeters respectively. The actual length (and width) can be 0.3 unit less than the measured length (and width) or 0.3 unit greater than the measured length (and width). a. Find the minimum and maximum possible lengths and widths of the book cover. b. Calculate the minimum and maximum possible areas of the book cover.
Part (a)
The length is supposed to be 22.2 cm, but it could be 0.3 cm less
So 22.2 - 0.3 = 21.9 cm is the smallest value for the length. This is the lower bound of the length.
The upper bound is 22.2 + 0.3 = 22.5 cm as it is the largest the length can get.
-------------
Use this for the width as well
The width is supposed to be 12 cm, but it could be as small as 12-0.3 = 11.7 cm and as large as 12+0.3 = 12.3 cm
-------------
Answers:smallest length = 21.9 cmlargest length = 22.5 cmsmallest width = 11.7 cmlargest width = 12.3 cm============================================
Part (b)
Use the smallest length and width to get the smallest possible area
smallest area = (smallest width)*(smallest length) = 11.7*21.9 = 256.23
-------------
Repeat the same idea but for the largest length and width to get the largest possible area
largest area = (largest width)*(largest length) = 12.3*22.5 = 276.75
-------------
Answers:smallest area = 256.23 square cmlargest area = 276.75 square cmCombine the radicals. 3√5-8√5+2√5
Answer: [tex]-3\sqrt{5}[/tex]
-3 times the square root of 5
=============================================
Explanation:
Let [tex]x = \sqrt{5}[/tex]
Replace all the root 5 terms with x and we go from
[tex]3\sqrt{5}-8\sqrt{5}+2\sqrt{5}[/tex]
to
[tex]3x-8x+2x[/tex]
From here, combine like terms to get
[tex]3x-8x+2x = -5x+2x = -3x[/tex]
and the last thing to do is replace the x with sqrt(5)
[tex]-3x = -3\sqrt{5}[/tex]
Meaning that,
[tex]3x-8x+2x = -3x[/tex]
[tex]3\sqrt{5}-8\sqrt{5}+2\sqrt{5} = -3\sqrt{5}[/tex]
The price of a stock decreased by 60 cents one week, decreased 10 cents the next week, and decreased another 20 cents the following week. What is the average change in the price of the stock over the three weeks? need to know right now ASAP!! –270 cents per week –90 cents per week –87 cents per week –30 cents per week
Hi there! Hopefully this helps!
----------------------------------------------------------------------------------------------------------
It decreased by 30 cents per week.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The average rate of change is calculated as:
the ratio of the sum of the change in the three weeks divided by the number of weeks. (The number of weeks being 3)
Rate of change = [tex]\frac{-60 -10 -20}{3}[/tex].
(-60 + -10 + -20 = -90). So, to simplify it:
[tex]\frac{-90}{3}[/tex] = -30
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Incase you are confused:
Since the average rate of change is negative, this means that the stock price has decreased.
what is (a x b) x c, if a = 11, b = 9, and c = 1? PLEASE HELP!!!
Answer:99
Step-by-step explanation:(11×9)×1=99
Answer:
The answer is 99Step-by-step explanation:
(a x b) x c
a = 11, b = 9, and c = 1
In order to solve substitute the values of a , b and c into the above expression
That's
( 11 × 9) × 1
Solve the terms in the bracket first
99 × 1
We have the final answer as
99Hope this helps you
when a watch is sold at ksh.126 a loss of x% is made if sold at ksh.154 aprofit of x%is realized .find the buying price
Answer:
ksh 140.
Step-by-step explanation:
when a watch is sold at ksh.126 a loss of x%. This can be summarised as follow:
Selling price (Sp) = ksh 126
Percentage loss = x%
Cost price (Cp) =?
Percentage loss = Cp – Sp/Cp x 100
x% = Cp – 126/Cp .......(1)
if sold at ksh.154 a profit of x% is realized. This can be summarised as follow:
Selling price (Sp) = ksh 154
Percentage gain = x%
Cost price (Cp) =?
Percentage gain = Sp – Cp/Cp x 100
x% = 154 – Cp/Cp..... (2)
Equating equation 1 and 2, we have:
x% = Cp – 126/Cp .......(1)
x% = 154 – Cp/Cp..... (2)
Cp – 126/Cp = 154 – Cp/Cp
Cross multiply
Cp(Cp – 126) = Cp(154 – Cp)
Cancel out Cp
Cp – 126 = 154 – Cp
Collect like terms
Cp + Cp = 154 + 126
2Cp = 280
Divide both side by 2
Cp = 280/2
Cp = 140
Therefore, the cost price otherwise known as the buying price is ksh 140.
A blueprint for a house has a scale factor n = 35. A wall in the blueprint is 10 in. What is the length of the actual wall?
29.17 in.
29.17 feet
350 feet
4,200 feet
Answer:
29.17 feet
Step-by-step explanation:
10 x 35 = 350 in. / 12 in/ft = 29.17 feet
The length of the actual wall is 29.17 feet. The correct answer is option B.
What is the scale factor?The scale factor is defined as the proportion of the new image's size to that of the previous image. decision-making.
It is given that the blueprint for a house has a scale factor of n = 35. A wall in the blueprint is 10 in.
The length of the actual wall is calculated as:-
L = 10 x 35
L = 350 in. / 12 in/ft
L= 29.17 feet
Therefore, the length of the actual wall is 29.17 feet. The correct answer is option B.
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Just need to calculate the area of the shaded region, thanks
Answer:
Area of the shaded region= 82.2 cm²
Step-by-step explanation:
Please see attached picture for full solution.
In a family with children, the probability that all the children are girls is appoximately . In a random sample of 1000 families with children, what is the approximate probability that or fewer will have girls? Approximate a binomial distribution with a normal distribution.
Answer:
The probability that 100 or fewer will have 3 girls is 0.00734.
Step-by-step explanation:
The complete question is:
In a family with 3 children, the probability that all the children are girls is approximately 0.125. In a random sample of 1000 families with 3 children, what is the approximate probability that 100 or fewer will have 3 girls? Approximate a binomial distribution with a normal distribution.
Solution:
Let X represent the number of families who has 3 girls.
The random variable X follows a Binomial distribution with parameters n = 1000 and p = 0.125.
But the sample selected is too large.
So a Normal approximation to binomial can be applied to approximate the distribution of X if the following conditions are satisfied:
1. np ≥ 10
2. n(1 - p) ≥ 10
Check the conditions as follows:
[tex]np=1000\times 0.125=125>10\\\\n(1-p)=1000\times (1-0.125)=875>10[/tex]
Thus, a Normal approximation to binomial can be applied.
So, [tex]X\sim N(\mu=np,\sigma^{2}=np(1-p))[/tex]
The mean and standard deviation are:
[tex]\mu=np=1000\times 0.125=125\\\\\sigma=\sqrt{np(1-p)}=\sqrt{1000\times 0.125\times (1-0.125)}=10.46[/tex]
Compute the probability that 100 or fewer will have 3 girls as follows:
Apply Continuity correction:
[tex]P(X\leq 100)=P(X<100-0.50)[/tex]
[tex]=P(X<99.50)\\\\=P(\frac{X-\mu}{\sigma}<\frac{99.5-125}{10.46})\\\\=P(Z<-2.44)\\\\=0.00734[/tex]
*Use a z-table.
Thus, the probability that 100 or fewer will have 3 girls is 0.00734.
Which of the following describe an angle with a vertex at A?
Check all that apply.
OA. ZABC
B. ZCAB
C. ZACB
D. ZBAC
Answer:
D) BAC is the correct answer as A is at the middle.
All of the options describe an angle with a vertex at A.
What is a vertex?In geometry, a vertex is a point where two or more lines, curves, or edges meet to form an angle or a corner.
It is the common endpoint of two or more rays, line segments, or sides of a polygon.
We have,
All of the options describe an angle with a vertex at A.
In each option, A is the vertex of the angle.
The letters that come before and after A indicate the other two points that form the angle. So:
∠ABC is an angle with vertex A and points B and C on either side.
∠CAB is an angle with vertex A and points C and B on either side. (Note that the order of the letters is reversed from option A.)
∠ACB is an angle with vertex A and points C and B on either side. (Note that the order of the letters is reversed from option B.)
∠BAC is an angle with vertex A and points B and C on either side. (Note that the letters are in a different order than option A.)
Thus,
All of the options describe an angle with a vertex at A.
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A study found that the expected annual income in a certain area is $17,255. Which of the following statistical measurements most likely led to this conclusion? Mean, range, median or mode?
Answer:
Mean
Step-by-step explanation:
mean is the average of numbers put together and divided by the total amount of numbers, when finding the average annual income using the mean would be most effective
Simplify:
[tex] \sqrt[4]{6 ^{4} } [/tex]
Answer:
6
Step-by-step explanation:
Doing the fourth root of something is the equivalent of doing said number to the power of 1/4. So in this case I will convert the fourth root into an exponent and simplify:
6^(4*1/4) = 6^1 = 6
Hope this helps!
If two of the ordered pairs was removed which two data points will cause the correlation to decrease the most? Select Two points
1) Data point A
2) Data point B
3) Data point C
4) Data point D
Answer:
1. Data point A
4. Data point D
Step-by-step explanation:
In a scatter plot, the closer the clustered data points are close to the best line of fit, the greater the correlation that would exist between the two variables.
If we are to draw a best line of fit in the scatter plot that is shown above, the closest data points amongst data points A, B, C, D, and E, that would be close to the best line of fit are data points A and D.
Therefore, removing data point A and point D would cause the correlation to decrease the most.
Complete the statements. f(4) is . f(x) = 4 when x is
Answer:
x=4
Step-by-step explanation:
it's a identity function because it is in the form of f(x)= x ,so the value of x is 4.
If Ab = 54, find MC.
Answer:
MC = 45
Step-by-step explanation:
Δ ABH and Δ MCH are similar and the ratios of corresponding sides are equal, that is
[tex]\frac{AB}{MC}[/tex] = [tex]\frac{AH}{MH}[/tex] , substitute values
[tex]\frac{54}{MC}[/tex] = [tex]\frac{6}{5}[/tex] ( cross- multiply )
6MC = 270 ( divide both sides by 6 )
MC = 45
In a given set of data, if the variance is 25, what is the standard deviation? *
Explanation: apply the square root to the variance to get the standard deviation
standard deviation = sqrt(variance)
variance = (standard deviation)^2
Based on the variance of the set of data and the definition of standard deviation, the standard deviation here must be 5.
Standard deviation allows us to measure how far apart variables are in a data set.
It is calculated as:
= √Variance
= √25
= 5
In conclusion, the standard deviation is 5 .
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The difference of two trinomials is x2 − 10x + 2. If one of the trinomials is 3x2 − 11x − 4, then which expression could be the other trinomial? 2x2 − x − 2 2x2 + x + 6 4x2 + 21x + 6 4x2 − 21x – 2
Answer:
[tex]4x^2-21x-2[/tex]
Step-by-step explanation:
Given that:
Difference of two trinomials is [tex]x^2 - 10x + 2[/tex]
One of the two trinomials is [tex]3x^2 - 11x - 4[/tex]
To find:
The other trinomial = ?
Four options are:
[tex]2x2 - x - 2 \\2x2 + x + 6 \\4x2 + 21x + 6\\ 4x2 - 21x - 2[/tex]
Solution:
Let the two trinomials be A and B.
Given A - B = [tex]x^2 - 10x + 2[/tex]
B = [tex]3x^2 - 11x - 4[/tex]
We have to find the other trinomial A.
A - B = [tex]x^2 - 10x + 2[/tex]
A - ([tex]3x^2 - 11x - 4[/tex]) = [tex]x^2 - 10x + 2[/tex]
[tex]\Rightarrow[/tex] A = [tex]x^2 - 10x + 2[/tex] + ([tex]3x^2 - 11x - 4[/tex])
[tex]\Rightarrow[/tex] A = [tex]4x^2-21x-2[/tex]
So, the correct answer is [tex]4x^2-21x-2[/tex].
PLEASE ANSWER QUICKLY ASAP
READ THE QUESTION CAREFULLY PLEASE
Answer:
140°
Step-by-step explanation:
total angle of a hexagon is 720. We know already 510°. That leaves 210°. The ratio between the two angles is 2:1, therefore angle CDE is 140° and angle DEF is 70 °
Answer:
140°
Step-by-step explanation:
We know that all of these angles here are part of a hexagon, meaning that their angle measures will all add up to 720°.
We can use what we already know and find what CDE and DEF will add up to.
[tex]145+90+160+115=510\\720-510=210[/tex]
Now, assuming x is the measure of DEF, we can create an equation for this.
[tex]x + 2x = 210\\3x = 210\\x = 70[/tex]
This is the measure of DEF, but it asks for CDE, which is twice the size of DEF. So
[tex]70\cdot2=140[/tex]
We can double check this is right by adding up all the measures.
[tex]145+90+160+115+140+70=720[/tex]
Hope this helped!
Sue likes to run. One day she was running for 3 hours with an average speed of 7 miles per hour. How many miles did she run that day?
Answer:
21 miles
Step-by-step explanation:
Since every single hour she runs 7miles.
In 3 hours she will run 7*3 miles.
21 miles
Hey there! I'm happy to help!
If Sue ran with an average speed of 7 miles an hour for 1 hour, she would have run 7 miles. So, if she ran at this speed for 3 hours, she would have run 3 times the distance she would if she ran for one hour!
7×3=21
Therefore, Sue ran 21 miles that day.
Have a wonderful day! :D
Barbara Cusumano worked 60 hours last week. Of those hours, 40 hours were paid at the regular-time rate of $12.50 an hour, 18 hours at the time-and-a-half rate, and 2 hours at the double-time rate. What was Barbara's gross pay for the week?
Answer:
$887.50
Step-by-step explanation:
Her gross pay is the sum of the pay amounts for each of the hour amounts:
pay = 40(12.50) +18(12.50)(1.5) +2(12.50)(2)
= (12.50)(40 +18(1.5) +2(2)) = 12.50(40 +27 +4) = 12.50(71)
pay = 887.50
Barbara's gross pay for the week was $887.50.
Find the area of quadrilateral...
Answer:
Total area = 29.8 sq. units
Step-by-step explanation:
area of each triangle = sqrt(s * (s-a) * (s-b) * (s-c))
to get the value of s, use the semi-perimeter = s = perimeter / 2
Total area = area of triangle ABD + area of triangle ACD
semi-perimeter of ABD = (3.48 + 8.66 + 8.6) / 2 = 10.37
semi-perimeter of ABD = (3.54 + 8.84 + 8.6) / 2 = 10.49
area of triangle ABD = sqrt(10.37 * (10.37-3.48) * (10.37-8.66) * (10.37-8.6))
area of triangle ABD = 14.7 sq. units
area of triangle ACD = sqrt(10.49 * (10.49-3.54) * (10.49-8.84) * (10.49-8.6))
area of triangle ACD = 15.08
Total area = 14.7 + 15.1
Total area = 29.8 sq. units
In the expression 3x2 + y -5, which of the following terms does not have a variable?
A.3x2
B. y
A
C. -5
D. None of these choices are correct.
Answer:
A, C
Step-by-step explanation:
Only B is containing a variable .
The -5 is not variable.
We have given that,
A.3x2
B. y
A
C. -5
In the expression 3x^2 + y -5
We have to determine which of the following terms does not have a variable.
What is the variable?
variable, In algebra, a symbol stands in for an unknown numerical value in an equation. Commonly used variables include x and y (real-number unknowns), z (complex-number unknowns), t (time), r (radius), and s (arc length).
Only C contains a variable.
The -5 is not variable.
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The sum of two consecutive odd integers is at least 36, find the integers
Answer:
The two integers are greater than or equal to 17 and 19
Step-by-step explanation:
Consecutive odd integers means 1, 3, 5, 7, 9 and so on
That means there is a always a gap of 2 in between each of them. Knowing this, we can set up an equation. Let x represent the first of the consecutive integers.
x+(x+2)=36
x+2 represents the second consecutive interger
x+x=34
2x=34
x=17
The two integers are 17 and 19
how do you find the surface area of this triangular prism?
To find the area of a triangular prism you have to do A 1/2 bh or A bh/2 which means you have to multiply those two fractions and reduce them
Answer:
Find the area of the 2 triangle faces first and then find the area of the 3 rectangle faces and add them together to get [tex]159cm^{2}\\[/tex]
Step-by-step explanation:Step 1: Find the surface area of the 2 triangles
[tex]\frac{(6)(5.5)}{2}[/tex] x2 = [tex]33cm^2\\[/tex]
Step 2: Find the surface area of the 3 rectangles
(6x7) x 3 = [tex]126cm^2[/tex]
Step 3: Add the 2 surface areas together
[tex]33cm^2\\[/tex] + [tex]126cm^2[/tex] = [tex]159cm^2[/tex]
Therefore the surface area of the prism is [tex]159cm^{2}[/tex]
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Factor completely 16x2 + 40x + 25. (4x − 5)(4x − 5) (2x − 5)(2x − 5) (2x + 5)(2x + 5) (4x + 5)(4x + 5) And this one please!
Select the polynomial that is a perfect square trinomial. 36x2 − 4x + 16 16x2 − 8x + 36 25x2 + 9x + 4 4x2 + 20x + 25
Answer:
(4x + 5)²
4x² + 20x + 25
Step-by-step explanation:
Step 1: Factor 16x² + 40x + 25
(4x + __)(4x + __)
What multiplies to 25 and adds up to 40 with 4 multiplied as coefficient?
(4x + 5)(4x + 5) or (4x + 5)²
Step 2: Factor perfect square trinomial
36x² - 4x + 16 --> 4(9x² - x + 4) No
16x² - 8x + 36 --> 4(4x² - 2x + 9) No
25x² +9x + 4 --> 25x² + 9x + 4 No
4x² + 20x + 25 --> (2x + 5)(2x + 5) or (2x + 5)² Yes
Answer:
(4x + 5)(4x + 5).
4x^2 + 20x + 25.
Step-by-step explanation:
16x^2 + 40x + 25
= (4x + 5)(4x + 5)
= (4x + 5)^2.
36x^2 − 4x + 16: To be a perfect square trinomial, the factors would have to be (6x + 4) or (6x - 4). Since the value of b is only -4, this is NOT a perfect square trinomial.
16x^2 − 8x + 36: To be a perfect square, factors would have to be (4x + 6) or (4x - 6). Since the value of b is only -4, this is NOT a perfect square.
25x^2 + 9x + 4: To be a perfect square, factors have to be (5x + 2) or (5x - 2). Since b is positive, factors would be (5x + 2)(5x + 2) = 25x^2 + 20x + 4. 20x is not equal to 9x, so this is NOT a perfect square.
4x^2 + 20x + 25: Perfect square would have to have factors (2x + 5) or (2x - 5). b is positive, so factors are (2x + 5)(2x + 5) = 4x^2 + 10x + 10x + 25 = 4x^2 + 20x + 25. This IS a perfect square!
Hope this helps!
