Find the solution of 2x - 2y = -20 and -2x + 4y = 14

We will use the elimination by addition/subtraction method to solve for y:

Given   2x - 2y = -20 and -2x + 4y = 14, add the second equation to the first:

 2x - 2y = -20 
 -2x + 4y = 14

          2y   = -6.  Solving for y:  y = -3.

Find x by subst. y=-3 into either of the given equations.

If we choose the first equation, then it becomes 2x - 2(-3) = -20

Solve this for x:  2x + 6 = -20, or 2x = -26, or x = -13.

The solution is (-13,-3).