8th Grade · Expressions & Equations
Inverse Operation
8.EE.C.7b
Definition
The operation that reverses another, such as subtraction undoing addition or division undoing multiplication. Used to isolate the variable when solving equations.
Examples
- For 2x+3=11: subtract 3 (inverse of +3), then divide by 2 (inverse of ×2).
- Undo operations in reverse order — addition/subtraction first, then multiplication/division.
Key rule
Apply the same inverse operation to both sides to keep the equation balanced.
Memory hook
Undo each operation with its opposite.