Subtract 6x over so you have y - 6x = 11, and 2y - 4x = 14. This is a system of equations. Multiply the first equation by 2 to get 2y - 12x = 22. By subtracting the second equation from the first, you get 8x = -8. So, x = -1. Plug that into the first equation and y = 5. Plug both of those answers into the equation to check. 2(5) - 4(-1) = 14, 14 = 14. The answers y = 5, and x = -1 check out.