7th Grade · Expressions & Equations
Inverse Operations
7.EE.B.4a
Definition
Pairs of operations that undo each other. Addition and subtraction are inverses; multiplication and division are inverses. Used to isolate the variable.
Examples
- x + 5 = 9 → subtract 5 from both sides → x = 4.
- 3x = 21 → divide both sides by 3 → x = 7.
Key rule
Use inverse operations to isolate the variable when solving equations.
Memory hook
Whatever was done, undo it.