How to use elimination?

You try to find the number and variables that cancels out or equal to 0 when added together between 2 equations, so if you choose to eliminate the x of the equations, lets say the first equation has - 2x in its given, make sure the next equation has 2x, then you add them together which will equal 0. Elimination is basically making sure your desirable variable equal to 0 when added together.