28+х=28 х-74=0 у+6=12
1.х=28-28 х=0 2.х=74+0 х=74 3.у=12-6 у=6
1 - 28+X=28 X=28-28 X=0 2 - X-74=0 X=0+74 X=74 2- y+6=12 y=12-6 y=6