To solve the equation \( x - 78 = -5 \) for \( x \), you need to isolate \( x \).
To do this, you can add \( 78 \) to both sides of the equation. This will eliminate the \(-78\) on the left side.
Here’s how it works:
Starting with the equation: \[ x - 78 = -5 \]
Add \( 78 \) to both sides: \[ x - 78 + 78 = -5 + 78 \]
This simplifies to: \[ x = 73 \]
So, the number that should be added to both sides of the equation is \( 78 \) in order to find the value of \( x \).