To solve the equation \(5y - 10 = -25\), we can follow these steps:
Step 1: Add 10 to both sides
\[ 5y - 10 + 10 = -25 + 10 \] This simplifies to: \[ 5y = -15 \]
Step 2: Divide both sides by 5
\[ \frac{5y}{5} = \frac{-15}{5} \] This simplifies to: \[ y = -3 \]
Thus, the solution is \(y = -3\).