We've already learned that we can add or subtract something from both sides of an equation.

So, what if we need to solve something like this?

4x = 20

(Yep,  the answer is 5.  I know you can see it... 
But, we need to learn the game.)

We need to get the x alone...

4x = 20
We need to get this 4 out of here...

What's he doing to the x?  Multiplying!
What's the opposite of multiplying?  Dividing!

So, divide both sides by 4:

4x / 4 = 20 / 4

Here's what's going on with this thing:

4x / 4 = (4/4)x = 1x = x     So, 4x / 4 = 20 / 4   which gives  1x = 5   which is  x = 5