To figure out the systems it is a simple equation of substitution and process of elemination. For example, equation two you would simply divide by 2 on both sides to get x=5. Then you will plug in 5 for x in x-y=3. 5-y=3 you would subtract five on both sides and get -2=-y. You would then divide -1 on both sides. And get y=2. And that’s about it.