x-y=3<span>-х-4у=7x-y=3</span>
y=x-3-х-4у=7-х-4*(x-3)=7
-x-(4x-12)-7=0
-x-4x+12-7=0
-5x+12-7=0
-5x+5=0
x=5/5
x=1x-y=31-y=3
y=-2Ответ: x=1; y=-2.