If you plug in (3x-5) in for y in the 6x+3y=15, you will get 6x+9x-15=15. Add the like terms (6x+9x) and get 15x. Bring the -15=15 down. Add 15 to the other 15 on the other side of the equal sign, bring 15x down and then divide 15 by 30 and get x=2. Plug in 2 for x in the (3x-5) equation, then solve and the answer will be y=1.
