The problem asks to prove that if $25 = -7(y - 3) + 5y$, then $y = -2$.

1. Problem Description

The problem asks to prove that if $25 = -7(y - 3) + 5y$, then $y = -2$.

2. Solution Steps

We start with the given equation and simplify it.

$25 = -7(y - 3) + 5y$

Distribute the $-7$ to the terms inside the parentheses:

$25 = -7y + 21 + 5y$

Combine the $y$ terms:

$25 = -2y + 21$

Subtract 21 from both sides of the equation:

$25 - 21 = -2y + 21 - 21$

$4 = -2y$

Divide both sides by $-2$:

$\frac{4}{-2} = \frac{-2y}{-2}$

$-2 = y$

Therefore, $y = -2$.

3. Final Answer

$y = -2$