Mathematics for IGCSE & O level - Equations (Section 8 - No. 27)
What must be done to both sides of an equation when changing the subject of a formula?
The same operation must be done.
Different operations can be used.
Only the right side needs to be changed.
Only the left side needs to be changed.
Explication
To keep the equation balanced, you have to maintain equality by doing the same thing to both sides.