2x+y=9 (*2) __ 4x+2y=18 name it 1. 8x-2y=6 name it 2. Now add both equations, 1 & 2. 4x+2y+8x+-2y=18+6. 2y will be cancelled out. You'll be left with 12x=24, x=2. Then replace the value of x which is 2 in either equation 1 or 2. I'll go with 1 equation 4(2)+2y=18 2y=18-8=10 y=5. Using the equation 2 should provide the same result of y.