1.∑4x-y=9 (*7
∑3x+7y=-1
∑28x-7y=63
31x=62
x=2
4*2-y=9
8-y=9
y=8-9
y=-1
ответ:x=2;y=-1
2.∑x+8y=-6
∑5x-2y=12 (*4
∑x+8y=-6
∑20x-8y=48
21x=42
5*2-2y=12
10-2y=12
2y=10-12
y=-2/2
1.∑4x-y=9 (*7
∑3x+7y=-1
∑28x-7y=63
∑3x+7y=-1
31x=62
x=2
4*2-y=9
8-y=9
y=8-9
y=-1
ответ:x=2;y=-1
2.∑x+8y=-6
∑5x-2y=12 (*4
∑x+8y=-6
∑20x-8y=48
21x=42
x=2
5*2-2y=12
10-2y=12
2y=10-12
y=-2/2
y=-1
ответ:x=2;y=-1
2)