We have two reliable methods of solving this simultaneous equation. We can either eliminate the variables (x or y) directly, or make one of the variables the subject of the equation. I will show you how to eliminate the variables: 2x + y = 7 and 3x - y = 8. This reduces to 5x = 15. Therefore, x = 3. And putting back into one of the equations, we can see that y = 1.