Hi
5x²-x-4 = 0
Δ= (-1)² - 4*5*(-4)
Δ = 1 -4*-20
Δ = 1 +80
Δ = 81
√Δ= 9
as Δ ≥ 0 , so 2 solutions exist in R
S1 is : ( 1+9) /2*5 = 10/10 = 1
s2 = (1 -9)/2*5 = -8/10 = -4*2 /2*5 = -4/5
Corrects answers are A and D
Answer:
A. -4/5 And D. 1
Step-by-step explanation:
i just got it right
Mr. Ellington has a total of 32 students in his class , The ratio of girls to boys is 3:5, how many girls are in Mr . Ellington's class ?
Add the ratio: 3 + 5 = 8
Divide total students by that:
32/8 = 4
The ratio for girls is 3, multiply the 4 by 3:
4 x 3 = 12
There are 12 girls
Answer:
12
Step-by-step explanation:
If the ratio of girls to boys is 3:5, that means that for every 8 total students, 3 would be girls and 5 would be boys. Therefore 3/8 of the students are girls and 5/8 are boys. If 3/8 are girls, then:
[tex]\frac{3}{8}[/tex] of 32
= [tex]\frac{3}{8} * 32[/tex]
[tex]=\frac{3 * 32}{8} \\= \frac{96}{8} \\= 12[/tex]
There are 12 girls.
Help anyone can help me do the question,I will mark brainlest.
Answer:
a) 30
b)600pi
Step-by-step explanation:
For the first questions, since the arc is 240°, the area of the sector and circumference will be 240/360 or 2/3 of the total of the circles'. Therefore 125.6 x 3/2 is the circumference, which is 188.4. When we divide this by 6.28, we get 30
Now, since the area is pi r^2 where we know that r=30, we get 900pi as the area of the whole thing, however since the sector is 2/3 of the whole circle, 2/3 x 900pi = 600pi
A chef mix his salt and pepper. If he put 2/3 cup of salt and 1/2 cup of pepper in his shaker, what is the ratio of salt to pepper ?
Answer:
4 to 3
Step-by-step explanation:
The ratio of salt to pepper is
2/3 to 1/2
Multiply both fractions by 6
6 * 2/3 to 6 * 1/2
4 to 3
The tens digits of a certain two-digit number is 1/3 of the units digit. When the digits are reversed, the new number exceed twice the original number by 2 more than the sum of the digits. Find the original number.
Answer:
The orginal number is 26.
Step-by-step explanation:
So the units digit can be 3 6 or 9
The tens digit can be 1 2 or 3
So the original number can be 13
31 = 2*13+ (1+3) + 2
31 =? 26 + 4 + 2
This doesn't work. The right side is 32
26
62 = 2*26 + 8 + 2
62 = 52 + 8 + 2
This is your answer.
3 and 9 won't work because 39 is odd and so is 93. The result has to be even.
indentify the explicit function for the sequence in the table
Answer:
Option B
a(n) = 8 + (n-1) • 6
Answered by GAUTHMATH
3 different problems.
solve b - 4 = 3.
solve -32 = 8w
solve n
— = -4
7
Answer:
see below
Step-by-step explanation:
b - 4 = 3
Add 4 to each side
b - 4+4 = 3+4
b = 7
-32 = 8w
Divide by 8
-32/8 = 8w/8
-4 = w
n/7 = -4
Multiply by 7 to each side
n/7 *7 = -4*7
n = -28
Independent Practice
Find the first, fourth, and eighth terms of the sequence.
an=0.5 · 3n−1a subscript n baseline equals 0.5 times 3 superscript n minus 1 baseline
A.
0.667; 4.5; 364.5
B.
3; 0.375; 0.0234375
C.
0.5; 13.5; 1093.5
D.
0.5; 121.5; 280.5
Answer:
C.
0.5; 13.5; 1093.5
Step-by-step explanation:
In the PQRS triangle PQ=QR, QR side extended to S Show that PQ+RS=QS. -S Q R
pls explain too
Answer:
Step-by-step explanation:
from the picture:
QP = QR
and
QR = RS
so
PQ + RS = QS
A plank 6m long leans against a vertical wall so that the foot of the plank is 4m away from the wall. A lizard climbs 2m up the plank. Calculate the horizontal distance between the lizard and the wall.
Answer: [tex]\dfrac{8}{3}\ m[/tex]
Step-by-step explanation:
Given
Length of the plank is [tex]6\ m[/tex]
Foot of the flank is [tex]4\ m[/tex] away from the wall
Lizard climbs 2 m up the wall
from the figure, the two triangles are similar
[tex]\therefore \dfrac{2}{6}=\dfrac{x}{4}\\\\\Rightarrow x=4\times \dfrac{2}{6}\\\\\Rightarrow x=\dfrac{4}{3}\ m[/tex]
So, the distance from the wall is
[tex]\Rightarrow 4-x\\\\\Rightarrow 4-\dfrac{4}{3}\\\\\Rightarrow \dfrac{8}{3}\ m[/tex]
You order CDs for $14.25 each and the website charges $4.50 for each shipment.
The expression $14.25p + $4.50 represents the cost of p CDs. Find the total cost for
ordering 4 CDs.
Answer:
$61.50
Step-by-step explanation:
14.25(4) + 4.50
= 57.00 + 4.50
= 61.50
There is 10% salt solution and a 30% salt solution. How much of each is needed to make 10L mixture that is 25% salt solution?
Answer:
2.5L of 10% salt solution and 7.5L of the 30% salt solution
Step-by-step explanation:
let the amount of L in the 10% solution be 'x'
let the amount of L in the 30% solution be '10-x'
* because they add up to a total of 10L
10%(x) + 30%(10-x) = 25%(10)
0.1x + 3 - 0.3x = 2.5
-0.2x = -0.5
x = 2.5
x =2.5
10-x = 7.5
2.5 of 10% solution and 7.5% of 30% solution
A person walks away from a pulley pulling a rope slung over it. The rope is being held at a height 10 feet below the pulley. Suppose that the weight at the opposite end of the rope is rising at 4 feet per second. At what rate is the person walking when s/he is 20 feet from being directly under the pulley
The image of this question is missing and so i have attached it.
Answer:
dd/dt = 4.47 ft/s
Step-by-step explanation:
From the image attached, let's denote the following;
d = horizontal distance beneath pulley
h = height of pulley
l = diagonal from the pulley to the head of the person
v = velocity of rope rising
Using pythagoras theorem;
l² = d² + h²
Differentiating with respect to time and considering h = c^(te) gives;
2l(dl/dt) = 2d(dd/dt)
We are given;
d = 20 ft
h = 10 ft
v = 4 ft/s
We know that velocity in this case is change in diagonal distance with time. Thus;
v = dl/dt = 4 ft/s
From earlier, we saw that;
2l(dl/dt) = 2d(dd/dt)
Thus, reducing it gives
(dl/dt)(l/d) = dd/dt
Now, l² = d² + h²
l = √(d² + h²)
Also, v = dl/dt = 4
Thus;
4(√(d² + h²))/d = dd/dt
4(√(20² + 10²))/20 = dd/dt
dd/dt = 4.47 ft/s
Write an equation in point-slope form of the line that passes through the given point and has the given slope.
(16,-4);m=-3/4
#What is the value of the discriminant for the quadratic equation –3 = –x2 + 2x?
Discriminant = b2 – 4ac
–8
4
8
16
Answer:
16
Step-by-step explanation:
the quadratic equation –3 = –x2 + 2x can be changed into :
x²-2x-3= 0
a=1, b= -2 , and c = -3
so, the discriminant = (-2)²-4(1)(-3)
= 4 + 12 = 16
Pls help me ! L need help here
Answer:
H. 40 inches
Step-by-step explanation:
On Wednesday, he is 40 inches taller. ... That would make 5 days of growth, for 100 inches. But this is only 3 days therefore he would grow 40 inches taller
20) solve:
[tex] {8}^{2} + 2 = [/tex]
21) solve:
[tex]4(2x + 5y = [/tex]
22) simplify the expression
[tex]4( {2}^{2} + 30) - 4 = [/tex]
given m||n, find the value of x
Answer:
x = 155º
Step-by-step explanation:
y = 25° {Vertically opposite angles}
x + y = 180 {Co-interior angles are supplementary}
x + 25 = 180
Subtract 25 from both sides
x = 180 - 25
x = 155°
The 12th term of the arithmetic sequence is 10.5. The 18th term of this sequence is 13.5. Find the common difference and the first term.
let the n'th term be called x, and the value of the term y,
then there is a function y=a*x + b
that will give us all term we want.
this formula is also used for straight lines.
we just need a and b. we already got two data points. we can just plug the known x/y pairs into the formula
10.5 = a*12 + b
13.5 = a*18 + b
now lets manipulate these lines.
multiply the first line by 3 and the second line by 2
31.5 = a*36 + 3b
27 = a*36 + 2b
subtract the second line from the first line
4.5 = b
yey, we now know b, let's plus b into either line from above, I'll go with the first one, looks easier.
10.5 = a*12 + 4.5
6 = a*12
0.5 = a
now y=a*x + b can be filled with a and b
y = 0.5 * x + 4.5
for x=1 (the first term) it's f(1)=5
each step is 0.5, hence the common difference.
2and way:(13.5-10.5)/(18-12)
= 3 / 6
= 0.5
we got the comment difference by looking at the full difference over 6 steps and divined by these 6 steps.
from step 12 to step one it's 11 steps down
10.5 - 0.5*11
= 10.5 - 5.5
= 5
okay I admit... 2and way to do it might be faster and more intuitive... :DA box contains a yellow ball, an orange ball, a green ball, and a blue ball. Billy randomly selects 4 balls from the box (with replacement). What is the expected value for the number of distinct colored balls Billy will select?
Answer:
[tex]Expected = 0.09375[/tex]
Step-by-step explanation:
Given
[tex]Balls = 4[/tex]
[tex]n = 4[/tex] --- selection
Required
The expected distinct colored balls
The probability of selecting one of the 4 balls is:
[tex]P = \frac{1}{4}[/tex]
The probability of selecting different balls in each selection is:
[tex]Pr = (\frac{1}{4})^n[/tex]
Substitute 4 for n
[tex]Pr = (\frac{1}{4})^4[/tex]
[tex]Pr = \frac{1}{256}[/tex]
The number of arrangement of the 4 balls is:
[tex]Arrangement = 4![/tex]
So, we have:
[tex]Arrangement = 4*3*2*1[/tex]
[tex]Arrangement = 24[/tex]
The expected number of distinct color is:
[tex]Expected = Arrangement * Pr[/tex]
[tex]Expected = 24 * \frac{1}{256}[/tex]
[tex]Expected = \frac{3}{32}[/tex]
[tex]Expected = 0.09375[/tex]
Write down at least five number pairs to solve the equation vw = 50
Answer:
1, 50
2, 25
5, 10
10, 5
25, 2
Answer:
Step-by-step explanation:
V W
1 x 50 = 50
1.5 x 33 1/3 = 50
2 x 25 = 50
2.5 x 20 = 50
3 x 16 2/3 = 50
3.5 x 14 2/7 = 50
4 x 12 1/2 = 50
4.5 x 11 1/9 = 50
5 x 10 = 50
5.5 x 9 = 50
6 x 8 1/3 = 50
6.5 x 7 2/3 = 50
7 x 7 1/7 = 50
7.5 x 6 2/3 = 50
8 x 6 1/4 = 50
8.5 x 5 8/9 = 50
9 x 5 5/9 = 50
9.5 x 5 1/4 = 50
10 x 5 = 50
10.5 x 4 3/4 = 50
11 x 4 5/9 = 50
11.5 x 4 1/3 = 50
12 x 4 1/6 = 50
12.5 x 4 = 50
13 x 3 6/7 = 50
13.5 x 3 5/7 = 50
14 x 3 4/7 = 50
Match the answers……………..
9 in 8956 = 900
9 in 95675 = 90000
9 = 9 in 124569
9 in 68795 = 90
90000 = 9 in 2549652.........
hope it helps...
A game involves correctly choosing the 5 correct numbers from 1 through 18 that are randomly drawn. What is the probability that a person wins the game, if they enter a) once? b) 7 times with a different choice each time?
Answer:
[tex]=\frac{1}{8568}\ = .00011\\\ =\frac{7}{8568} = .00081[/tex]
Step-by-step explanation:
[tex]5/18\cdot \:4/17\cdot \:3/16\cdot \:2/15\cdot \:1/14=\frac{1}{8568}[/tex]
please help, will give brainliest!!!
Answer:
≈ 0.19
Step-by-step explanation:
So first, we find the probability of getting 1 yellow marble (the formula is the number of amount of type over the total number of items), which is:
10/(6+10+5+1)
= 10/22
= 5/11.
So getting a yellow marble on the first try is 5/11 likeliness.
Now, for the second one, we do the same except that you are NOT putting it back into the bag, which means we have to subtract the yellow marble you already took AND ALSO ONE FROM THE TOTAL AMOUNT OF YELLOW MARBLES.
To find the probability of getting the second marble, our equation is:
9/(6+9+5+1)
= 9/21
= 3/7.
Lastly, to find the probability of getting them both consecutively, we multiply the two results.
5/11 * 3/7
= 15/77
≈ 0.19
I hope this helped! :D
Guys please help me solve this I’m struggling
Answer:
[tex]Max\ z = 1[/tex]
[tex]Min\ z = -9[/tex]
Step-by-step explanation:
Given
[tex]z = 4x + 5y[/tex]
[tex]x \ge -1[/tex]
[tex]y \le 2x +3[/tex]
[tex]y \le -1[/tex]
Required
The maximum and minimum of z
To do this, we make use of the graphical method
See attachment for graphs of
[tex]x \ge -1[/tex]
[tex]y \le 2x +3[/tex]
[tex]y \le -1[/tex]
The corner points of the function are:
[tex](x,y) = (-1,1)[/tex]
[tex](x,y) = (-1,0)[/tex]
[tex](x,y) = (-1,-1)[/tex]
We have:
[tex]z = 4x + 5y[/tex]
Calculate z with the above values
[tex]z = 4(-1) + 5(1) = 1[/tex]
[tex]z = 4(-1) + 5(0) = -4[/tex]
[tex]z = 4(-1) + 5(-1) = -9[/tex]
So, we have:
[tex]Max\ z = 1[/tex]
[tex]Min\ z = -9[/tex]
Find a 2-digit number smaller than 50, the sum of whose digits does not change after being multiplied by a number greater than 1
The only 2-digit number that is lesser than 50 and the sum of its digits remain unaffected despite being multiplied by a number < 1 would be '18.'
To prove, we will look at some situations:
If we add up the two digits of 18. We get,
[tex]1 + 8 = 9[/tex]
And we multiply 18 by 2 which is greater than 1. We get,
[tex]18[/tex] × [tex]2 = 36[/tex]
The sum remains the same i.e. [tex]3 + 6 = 9[/tex]
Similarly,
If 18 is multiplied to 3(greater than 1), the sum of the two digits comprising the number still remains the same;
[tex]18[/tex] × [tex]3 = 54[/tex]
where (5 + 4 = 9)
Once more,
Even if 18 is multiplied to 4 or 5(greater than 1), the sum of its digits will still be 9.
[tex]18[/tex] × [tex]4 = 72[/tex]
[tex](7 + 2 = 9)[/tex]
[tex]18[/tex] × [tex]5 = 90[/tex]
[tex](9 + 0 = 9)[/tex]
Thus, 18 is the answer.
Learn more about 'numbers' here: brainly.com/question/1624562
Use the Diagram to find BC.
Answer:
Step-by-step explanation: you have to ask your parents for help
Rhombus LMNO is shown with its diagonals.
Rhombus L M N O is shown. Diagonals are drawn from point L to point N and from point M to point O and intersect at point P. All sides are congruent.
Angle MNO measures 112°. What is the measure of angle LMN?
Answer:
hope this help
Step-by-step explanation:
Answer:
90
51
10
Step-by-step explanation:
working alone, aliyah can dig a 10ft by 10 ft hole is 6 hours. one day her friend eugene helped her and it only took 3.75 hours. how long would it take eugene to do it alone? disclaimer: the answer is 11.95 hours, but i keep getting 10. please use the 1/x+1/y=1/z strategy
Answer:
I think the answer is 10 hours
the 11.95 seems wrong
Step-by-step explanation:
[tex]\frac{1}{6} + \frac{1}{y} = \frac{1}{3.75}[/tex]
multiply by 22.5 y
3.75 y + 22.5 = 6y
y = 10
What is (0,6] n (6,8]?
Answer:
(6) the letter n : intersection which means the number you will find at the first bracket and has the same number at the other bracket
Value of the boat after 3 years?
after each year it's 83% of it's value from last year (100%-17%=83%)
the function in 19000 * (0.83) ^x
3 will be filled in for x
19000 * (0.83) ^3= 10863.953
$10863.95
Answer:
$10,863.95
Step-by-step explanation:
y = 19,000[tex](.83)^{t}[/tex]
y = 19,000[tex](.83)^{3}[/tex]
y =$10,863.95
