{x+y=7 2x+y=17

x = 7 - y 14 - 2y + y = 17 x = 7 - y -y = 3 /:(-1) y= -3 x= 10 pzdr ;)

{x+y=7 2x+y=17 x=7-y 14-y=17 y=-3 x=10