How do you isolate a variable in an equation?

Answer 1

You get rid of everything that is NOT the variable. Be sure to do the same operation on both sides. Here is an example:2x + 3 = 15

First, you might get rid of the 3. To do this, you need to subtract 3 on both sides:

2x + 3 - 3 = 15 - 3

2x + 0 = 12

2x = 12

Note: In practice, you will often write the last step directly. The previous steps are only to clarify what is going on.

Next, divide both sides by 2:

2x/2 = 12/2

x = 6