To solve the equation \( 5y - 10 = -25 \), you can follow these steps:
Step 1: Add 10 to both sides of the equation to isolate the term with \( y \):
\[ 5y - 10 + 10 = -25 + 10 \]
This simplifies to:
\[ 5y = -15 \]
Step 2: Divide both sides by 5 to solve for \( y \):
\[ y = \frac{-15}{5} \]
This simplifies to:
\[ y = -3 \]
Solution: The value of \( y \) is \(-3\).