For the first problem, multiply the top equation by 2, so the resulting equation is 16x-12y = -40. You notice that if you add the bottom equation to the top equation, the X’s cancel out, resulting in the equation: 5y = -10, so y = -2. Plug -2 into y, and x = -4. For the second problem, you can multiply the top equation by 5 resulting in: -20y-55x = 30. The bottom equation can be multiplied by -2 resulting in: 20y+20x = -40. Notice that the y’s can cancel if the top and bottom equation are added together.
