Question

How to solve? I basically want to know the first step..

Answer 1

In the equation x-y = 5 subtract x from both sides , and then divide by -y. so at the ned you will get what y equals to and plug that into your equation
2x-2y = 10.

Let me know if this is helpful :) <span />

Answer 2

You have to get x alone and then do the rest of the steps