{ х + у=6 {х + у=7 {4 х-3 у=-1 5 х-2 у=9; 5 х-7 у=11; х-5 у=4

1) x+y=65x-2y=9 x=6-y5 (6-y) -2y=930-5y-2y=9-7y=-21y=3x=6-3=3 2) x+y=75x-7y=11 x=7-y5 (7-y) -7y=1135-5y-7y=11-12y=-24y=2x=7-2=5 3) 4x-3y=-1x-5y=4 x=4+5y4 (4+5y) -3y=-116+20y-3y=-117y=-17y=-1x=4+5*(-1)=-1