2x-y=3
2x=3+y
x=3/2+y/2
2*3/2+y/2-y=3
3/2-y/2=3
-y/2=3-3/2
-y=3*2-3/2*2
-y=6-3
+y=-3
2x-y=3 2x+3=3
x=0
ответ x=0 y=-3
2x-y=3
2x=3+y
x=3/2+y/2
2*3/2+y/2-y=3
3/2-y/2=3
-y/2=3-3/2
-y=3*2-3/2*2
-y=6-3
+y=-3
2x-y=3 2x+3=3
x=0
ответ x=0 y=-3