Answer:
20cmStep-by-step explanation:
The Sydney Harbour Bridge is approximately 1200 metres long. A model of the bridge is built with a scale of 1:6000. What is the length of the model?
Pick one:
5cm
20cm
200cm
720cm
--------------------
scale = 1:6000
so
1200 : 6000 = 0.2m
0.2m = 20 cm
Answer:
20cm
Step-by-step explanation:
«A scale of 1:6000» means the model is smaller than the bridge by a factor of 6000. We can also make up a proportion [tex]\dfrac{1}{6000}=\dfrac{x}{1200}[/tex], where the left side is the scale, x is the model length, 1200 is the bridge length (in meters). So, finding x or just dividing 1200 by 6000, we get 0.2 meters. Provided 1 m = 100 cm, 0.2 m is 0.2 × 100 = 20 cm.
PLZ HELP!!!!
Use the function f(x)=x^2+4x-5 and the coordinate plane. SHOW ALL WORK FOR EACH PART!
What are the values of a, b, and c? (3pts)
Does the parabola open up or down? How do you know? (2pts)
What is the maximum or minimum value? How do you know? (2pts)
What are the x-intercepts? (2pts)
What is the y-intercept? (1pt)
What is the vertex? (2pt)
9514 1404 393
Answer:
a) a=1, b=4, c=-5
b) opens up; a > 0
c) minimum = -9, the y-value of the vertex
d) x = -5, 1
e) y = -5, the value of c
f) (-2, -9)
Step-by-step explanation:
A graph drawn by a graphing calculator can answer all of these questions quickly and easily.
__
a) The values of 'a', 'b', and 'c' are the values of the coefficients of the terms in the function definition. They refer to the coefficients in the standard form:
f(x) = ax^2 +bx +c
f(x) = x^2 +4x -5 . . . . . . . your equation with a=1, b=4, c=-5
__
b) The parabola opens up. This is because the value of 'a' is greater than zero.
__
c) The minimum is the y-value of the vertex. When the function is written in vertex form it is ...
f(x) = (x -h)^2 +k . . . . . . . . . . . vertex (h, k)
Your function can be put into this form:
f(x) = x^2 + 4x +4 -5 -4 . . . . . . add and subtract 4 to complete the square
f(x) = (x +2)^2 -9 . . . . . . . . vertex form. The vertex is (-2, -9).
The y-value of the vertex is -9, the minimum value of the function.
__
d) Solving f(x) = 0, you get ...
(x +2)^2 -9 = 0
(x +2)^2 = 9 . . . . . . . . add 9
x +2 = ±√9 = ±3 . . . . . take the square root; next, subtract 2
x = -2 ±3 = {-5, 1} . . . . . the x-intercepts
__
e) The y-intercept is f(0) = c = -5.
__
f) The vertex was found in part (c) to be (-2, -9).
Class 10R sat a test.
The mean mark for the class was 70%.
There are 30 students in class 10R, 20 of whom are boys.
The mean mark for the boys in the test was 62%.
Work out the mean mark for the girls.
86%
Step-by-step explanation:30 students in the class with a mean average of 70% can be expressed as:
total class percent / 30 = 70%
Rearranged, this gives that the class achieved a total of 30x70 or 2100%.
20 boys in the class with a mean average of 62% can be expressed as:
total boys percent / 20 = 62%
Rearranged, this gives that the boys achieved a total of 20x62 or 1240%.
This means that the girls achieved 2100 - 1240 so 860%.
Because there are 30 students and 20 boys, there are 10 girls.
Then work out the mean with a total of 860% and 10 girls.
860/10 = 86%.
Which best describes the error in finding the area of the parallelogram?
15 meters was used for the height instead of 13 meters.
15 meters was used for the height instead of 13 meters.
8 meters was used for the height instead of 13 meters.
8 meters was used for the height instead of 13 meters.
The product of 8 and 15 is not 120.
The product of 8 and 15 is not 120.
The formula to use should have been A=12bh instead of A=bh.
The formula to use should have been, cap A is equal to 1 half b h instead of cap A is equal to b h.
Question 2
Correct the error.
A=
=
m2
Answer:
104
Step-by-step explanation:
pls help ill give brainliest
Answer:
4
Step-by-step explanation:
-5g -6
Let g= -2
-5 (-2) -6
Multiply
10 -6
4
Answer:
A. 4
Step-by-step explanation:
So, we have an equation with a variable (g), and they've given us the value of g to be -2. All we have to do at this stage is plug in the value of g into the equation.
-5g-6 (g=-2)
-5(-2)-6
10-6=4
Doing the math by plugging in -2, you would get your answer to be 4. Let me know if you see any errors, and if you have any further questions at all.
combine like terms and solve x
12x + 3 - 4x - 6 = 5
5x - 4 + 7 + 6x - 4x = 24
Answer:
12x + 3 - 4x - 6 = 5
x=1
5x - 4 + 7 + 6x - 4x = 24
x=3
If an atom has 5 protons, 7 neutrons and 5 electrons what is the mass number of the atom?
Please help quick!
No links!
Answer:
7+5=12
Step-by-step explanation:
To calculate the mass number of an atom, you have to add the protons and the neutrons. We have 7 neutrons and 5 protons, so your mass number would be 12. Let me know if you have any further questions. :)
pls help fast
brainlest to enyone who helps
Answer:
B STEP 2
Step-by-step explanation:
5/8 is not more than 1
A scale drawing for a plot of land is shown below.
In the drawing, 5 cm represents 6 m.
Assuming the backyard is rectangular, find the area of the real backyard.
Answer:
72m
Step-by-step explanation:
since 5cm is 6m, just take 5 and make it 6, so 10cm is 12m and 5cm is 6m
multiply, and you get the answer
HELP GIVING BRAINLIEST (NO LINKS) 50 POINTS
Expression A: 2(x + 1)
Expression B: 2x + 2
which statement does not show that these expressions are equivalent
A.subsitiuting any value of x makes the expressions equivalent
B. Both expressions involve addition
C. The expressions name the same number regardless of the value of x
D. 2(x +1) can be rewritten as 2x + 2 using the distributive property
Explain why the square root of a number is defined to be equal to that number to the 1/2 power.
This is because of the law of indices which says:
[tex]\sqrt[x]{n}[/tex]= [tex]x^{\frac{1}{m} }[/tex]
So, if we have:
[tex]\sqrt{n}[/tex]
Then the following will be true because of this math law:
[tex]n^{\frac{1}{2} }[/tex]
Side note: The m value can be greater than n and or less than n, but if it is equal the m and n values cancel out.
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
Solve for n.
9 =
n
2
+ 7
n =
Answer:
9/n-2=7
We move all terms to the left:
9/n-2-(7)=0
Domain of the equation: n!=0
n∈R
We add all the numbers together, and all the variables
9/n-9=0
We multiply all the terms by the denominator
-9*n+9=0
We add all the numbers together, and all the variables
-9n+9=0
We move all terms containing n to the left, all other terms to the right
-9n=-9
n=-9/-9
n=1
Answer:
n = 1
Step-by-step explanation:
2 x 1 = 2
2 + 7 = 9
a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams. How much of the substance remains after 8 seconds?
Answer:
1.25 g
Step-by-step explanation:
you start with 20g at 0 seconds.
divide by half after 2 seconds and you have 10g.
at 4 seconds you have 5g.
at 6 seconds you have 2.5g.
at 8 seconds you have 1.25g.
The size of the substance after 8 seconds will be 1.25 g
What is an expression?The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
Given that a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams.
Start with 20g at 0 seconds and divide by half after 2 seconds and you have 10g.
4 seconds you have 5g.
6 seconds you have 2.5g.
8 seconds you have 1.25g.
To know more about an expression follow
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write a peacewise function for the graph
please help me
Answer:
[tex]\left \{ {{y=x; \ \ x\le 0} \atop {y=4+ \frac12x;\ \ x>0}} \right.[/tex]
Step-by-step explanation:
If you look at the graph you see that:
before 0, the graph has same y as it has x, or y=x.
after 0, the graph starts at 4, and increases by 1 every 2 steps horizontally, or has a slope of 1/2.
Finally, the 0 has to be included in the blue part of the graph based on where the solid dot is.
80% of __ is 16 help
Answer:
80% of 20 is 16.
Step-by-step explanation:
Hello darling, the answer is 20 ^^
2x2-5x-2 solve by quadratic formula 9leave answers in simplest radical form)
Answer:
-5x+2
Step-by-step explanation:
1. Multiply number 2 and 2=4 so it is
4-5x-2
2. Combine like terms
-5x+4-2
3. Subtract the numbers
-5x+2
Find the surface area of the square pyramid below.
Answer:
Step-by-step explanation:
Answer:
96 cm or B
Step-by-step explanation:
Base-l*w, 6*6, 36
Side 1-(h*w)1/2, (30)1/2, 15
Side 2-Same as 1
Side 3-Same as 1
Side 4-Same as 1
15+15=30, 15+15=30, 30+30=60, 60+36=96
96 cm
Express in vertex form
Y=2x^2 - 2x - 5
Answer:
y = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{11}{2}[/tex]
Step-by-step explanation:
y = 2x² - 2x - 5 ← factor out 2 from the first 2 terms
= 2(x² - x) - 5
Using the method of completing the square
add/subtract (half the coefficient of the x- term)² to x² - x
y = 2(x² + 2(- [tex]\frac{1}{2}[/tex] ) x + [tex]\frac{1}{4}[/tex] - [tex]\frac{1}{4}[/tex] ) - 5
= 2(x - [tex]\frac{1}{2}[/tex] )² + 2(- [tex]\frac{1}{4}[/tex] ) - 5
= 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{1}{2}[/tex] - 5
= 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{11}{2}[/tex] ← in vertex form
PLEASE HELP ASAP GIVING BRAINLIEST
Answer:
brainliest mo munako
Step-by-step explanation:
bago answer pede maliwaag ba
9. 2 less than 3 times a number is the same as 2114. What is the number?
Enter your answer as a decimal or simplified mixed number in the box. The number is.
Answer:
705.3 repeated I don't know if that's what you want but
3 times of 705.33 and 2 subtracted is equal to 2114.
What is Simplification?Simplification in mathematical terms is a process to convert a long mathematical expression in simple and easy form.
Given that,
2 less than 3 times a number equal to 2114.
Let the required number is x.
According to given condition,
3x - 2 = 2114
3x = 2114 + 2
3x = 2116
x = 2116 / 3
x = 705.33
The required number is 705.33.
To know more about Simplification on :
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help me please asap
Answer:
5/6
Step-by-step explanation:
2/
3
: 4/
5
= 2/
3
· 5/
4
= 2 · 5/
3 · 4
= 10/
12
= 2 · 5/
2 · 6
= 5/
6
Directions: Directions: Identify x1, x2, y1, and y2. Solve for the of the line passing through the given points. Identify if the slope is positive, negative, zero, or undefined.
1.(2,1) and (5,3)
2.(-2,1) and (1, -3)
3.(4,1) and (5,1)
4.(7,-1) and (7,5)
5.(-2,1) and (3,6)
Step-by-step explanation:
Number 1
m = (y2 - y1)/(x2 - x1)
m = (3 - 1)/(5 - 2)
m = 2/3 POSITIVE
Number 2
m = (y2 - y1)/(x2 - x1)
m = (-3 - 1)/(1 + 2)
m = -4/3 NEGATIVE
Number 3
m = (y2 - y1)/(x2 - x1)
m = (1 - 1)/(5 - 4)
m = 0/1
m = 0 ZERO
Number 4
m = (y2 - y1)/(x2 - x1)
m = (5 - 1)/(7 - 7)
m = 4/0
m = UNDEFINED
Number 5
m = (y2 - y1)/(x2 - x1)
m = (6 - 1)/(3 + 2)
m = 5/5
m = 1 POSITIVE
line j passes through the point (-4,10) and (2,-8). Line k passes through the point (1,2) and is parallel to line j. Find an equation for line k.
Answer:
344444444433333338694
Step-by-step explanation:
Answer: y = -3x+5
Step-by-step explanation:
solve pls brainliest
Answer:
64%
Step-by-step explanation:
Step 1: Divide 16 by 25
-> [tex]\frac{16}{25}[/tex] -> [tex]0.64[/tex]Step 2: Multiply quotient by 100.
[tex]0.64 * 100[/tex] [tex]6.4 * 10[/tex] [tex]64[/tex] 64%Therefore, 16/25 as a percentage is 64%.
Answer:
Well you can make a proportion
Percentage means ”Out of a hundred”
So you can make a proportion with any fraction Equal to x/100 since
X is the unknown perctange.
in this case it’s 16/25
16/25 = x/100
So cross multiply To solve for X
1600= 25x
x= 64
So 64 Percent
In this case you can use benchmarks. If you do it more or long enough, you’d memorize them.
In this case 25 is a bench mark of 1/4 or 25. 25 goes into 100 4 times so you can multiply 16 by 4 to get your percentage since if you do multiply 4, you have to do it to both the numerator and the Denominator.
so 16/25
16*4= 64
25*4=100
64/100 or 64 percent.
Common benchmarks for percentages
5, 10, 20, 25, 50
5 is always multiply by 20
10 is always multiply by 10
20 is always multiplied by 5
25 is always multiplied by 4
50 is always multiplied by 2
A car is moving at 12 m/s and has a mass of 600 kg. What is the kinetic energy of the car? (Formula: KE = 1/2mv^2) WILL GIVE BRAINLEST
Answer:
The kinetic energy of the car is 43,200 Joules.
Step-by-step explanation:
KE = (1/2)mv^2
KE = (1/2)(600 kg)(12 m/s)^2
KE = (1/2)(600 kg)(144 m^2/s^2)
KE = 43,200 kg*m^2/s^2 = 43,200 Joules
Answer:
Step-by-step explanation:
KE= 1/2mv^2
KE = 1/2(600) 12^2
KE = 300 * 144 = 43200J
can you find x and y
Answer:
yes
Step-by-step explanation:
Answer:
Yes
Step-by-step explanation:
Your answer is 5,7... Oh that's wrong you forgot to link a file bud
solutions: ( x = 2 & x = -2 )
hmmmmhmmmmmmmmmmmmmmmmmmmmmm
Can someone please help me solve this…
Answer:
C = 4s + 6a
C = 4(3) + 6(2)
C = 12 + 12
C = 24
-2x -3 for x = -3
( Evaluate the following algebraic expression )
Answer:
well its -2*-3-3 so
-2*-3 is 6-3 is 3
Step-by-step explanation:
why are prefixes used in naming covalent compounds
A. oxidation states of the atoms are identified with prefixes
B. the atoms can have different numbers of valence electrons
C. the prefixes identify the only way the atom can combine
D. the same atoms can combine in more than one ratio
Answer:
the atoms can have different numbers of valence electrons
If K = F( A + B ) , find “ A ” if F = 2 , B = 3 , K = 10
Answer:
The value of A is 2
Step-by-step explanation:
F = 2 , B = 3 , K = 10
K = F( A + B )
10 = 2(A + 3)
10 = 2A + 6
Now, Subtract 6 from each side we get,
10 - 6 = 2A + 6 - 6
4 = 2A
2A = 4
Now, divide both side by 2 we get,
2A/2 = 4/2
A = 2
Thus, The value of A is 2
FOR VERIFICATION ONLY :-K = F( A + B )
10 = 2(2 + 3)
10 = 2(5)
10 = 10
L.H.S = R.H.S
Hence Proved!
-TheUnknownScientist 72
