Answer:
C
Step-by-step explanation:
Add 10x to both sides:
-10x - 135 = 117 + 2x
-10x - 135 + 10x = 117 + 2x + 10x
-135 = 117 + 12x
Subtract 117 from both sides:
-135 - 117 = 117 + 12x - 117
-252 = 12x
Divide both sides by 12:

-21 = x
So the answer is C.
Hope this helps!
Answer:
see explanation
Step-by-step explanation:
In 13 - 17
Consider the factors of the constant term which sum to give the coefficient of the x- term
13
x² - x - 42 = (x - 7)(x + 6)
15
x² + x - 6 = (x + 3)(x - 2)
17
x² - 27x + 50 = (x - 25)(x - 2)
19
r² - 25 ← is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , thus
r² - 25
= r² - 5² = (r - 5)(r + 5)
Combine like terms. The 5x is grouped to the 8x and the -7 isgrouped with the -55.
This means 5x + 8x = 13x and -7 - 55 = -62
The new expression is 13x - 62. We can't find the exact value of x because the expression wasn't set equal to anything.
Based on the ratio of boys/girls We can infer that the only possibility for Ellen's math class would be answer B. 14/21