Question

How can you isolate the variable in this equation? x + 6 = 13

Answer 1

You can isolate the variable by subtracting 6 from both sides.

e.g.

x + 6 = 13

  -  6   - 6

Now we have x = 7, which not only isolates the variable but solves for x.

If you don't know why we can subtract from both sides, look up the Addition Property of Equality and Subtraction Property of Equality.