8th Grade · Expressions & Equations

Isolate

8.EE.C.8b

Definition

To get a variable by itself on one side of an equation using inverse operations. This is the goal when solving and the first step in substitution.

Examples

  • 3x+6=15: subtract 6 to get 3x=9, divide by 3 to get x=3.
  • Solve x+y=7 for y: y = 7-x.

Key rule

Use inverse operations to move every other term away from the variable.

Memory hook

Get the variable alone on one side.