4x+y=-2 x+2y=3

4x+y=-2 x+2y=3
4x+y=-2 x+2y=3

4x+y=-2 x+2y=3
x=-1 y=2

x＝-1

7x=-7
x=-1
7y=14
y=2

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7x=-7
x=-1
7y=14
y=2

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x=-1 y=2

收起

4x+y=-2 1)
x+2y=3 2)
2)式2边乘以4得
4x+8y=12 3)
3)-1)得
7y=14
解y=2
代入1）得x=-1
答：x=-1,y=2

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