To solve the equation \( 2x - 5 = -21 \), we can follow these steps:
Step 1: Add 5 to both sides of the equation.
\[ 2x - 5 + 5 = -21 + 5 \]
This simplifies to:
\[ 2x = -16 \]
Step 2: Divide both sides by 2.
\[ \frac{2x}{2} = \frac{-16}{2} \]
This simplifies to:
\[ x = -8 \]
Solution: The solution to the equation is \( x = -8 \).
So, in a summary format:
- Step 1: Add 5 to both sides.
- Step 2: Divide both sides by 2.
- Solution: \( x = -8 \)