What is (x,y) if y+2x=3 and y-x=-9
so use subsituteionmake y-x=-9change it to subsitutey-x=-9add x to both sidesy=x-9susitute x-9 for y in y+2x=3x-9+2x=33x-9=3add 9 both sides3x=12divide both sides by 3x=4subsitutey=x-9y=4-9y=-5x=4y=-5(4,-5)