1. This must be greater than or equal to 0 (there can't be any negatives!)
8 - .5t ≥ 0.
8 ≥ .5t
t ≤ 16
D.
2. 4(2x-1) = 2x + 35
8x - 4 = 2x + 35
6x = 39
x = 6.5
H.
3. c = .8(x-15) = .8x-12
A.
4. m = number of marble cupcakes
s = number of strawberry shortcake cupcakes
6m + 8.5s = 391
m = 1/2s
6(.5s)+8.5s = 391
11.5s = 391
s = 34
m = 17
F.
5. B
6. Use substitution
2x + 3x = 10
5x = 10
x = 2
7. (sorry I'm not sure!)
8. G
9. L = number of balls
B = number of bats
L + B = 100
B = 100 - L
4.5L+20B = 822
4.5L + 20(100-L) = 822
4.5L -20L + 2000 = 822
1178 = 15.5L
L = 76
10. J
Answer:
59 to 66
Step-by-step explanation:
Mean test scores = u = 74.2
Standard Deviation = 
= 9.6
According to the given data, following is the range of grades:
Grade A: 85% to 100%
Grade B: 55% to 85%
Grade C: 19% to 55%
Grade D: 6% to 19%
Grade F: 0% to 6%
So, the grade D will be given to the students from 6% to 19% scores. We can convert these percentages to numerical limits using the z scores. First we need to to identify the corresponding z scores of these limits.
6% to 19% in decimal form would be 0.06 to 0.19. Corresponding z score for 0.06 is -1.56 and that for 0.19 is -0.88 (From the z table)
The formula for z score is:
For z = -1.56, we get:
For z = -0.88, we get:
Therefore, a numerical limits for a D grade would be from 59 to 66 (rounded to nearest whole numbers)
The equation is -2x-4. u can use y2-y1/x2-x1.
Answer:
x= 2 and y = -4
Step-by-step explanation:
8x + 3y = 4 ---------------------------------(1)
-7x + 5y = -34 -----------------------------(2)
Multiply through equation (1) by 5 and multiply through equation(2) by 3
40x + 15y = 20 ----------------------------(3)
-21x + 15y =-102----------------------------(4)
Subtract equation (4) from equation (3)
61x = 122
Divide both-side of the equation by 61
61x/61 = 122/61
(At the left-hand side of the equation 61 will cancel-out 61 leaving us with just x, while at the left-hand side of the equation 122 will be divided by 61)
x = 122/61
x=2
Substitute x= 2 into equation (1)
8x + 3y = 4
8(2) + 3y = 4
16 + 3y = 4
Subtract 16 from both-side of the equation
16-16 + 3y = 4-16
3y = -12
Divide both-side of the equation by 3
3y/3 = -12/3
y = -4
x= 2 and y = -4
Answer:
5/9
Step-by-step explanation:
Start be letting x = 0.555...
Our original equation is:
x = 0.555...
There is only one digit repeating, the 5, so we multiply both sides of that equation by 10 and write it above the original equation.
10x = 5.555...
x = 0.555...
Now we subtract the second equation from the first equation as written above.
9x = 5
Divide both sides by 9.
x = 5/9
0.555... = 5/9
