解方程组2x-y=1 2y+x=8(代入法) 5x+2y=7 16x+9y=12(加减法) x-2y=3 2x-1/2y=6(用代入法)4x-3y=-1 4x+5y=7 (用加减法) 3x-2y=6 2x+3y=17(用加减法)
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![解方程组2x-y=1 2y+x=8(代入法) 5x+2y=7 16x+9y=12(加减法) x-2y=3 2x-1/2y=6(用代入法)4x-3y=-1 4x+5y=7 (用加减法) 3x-2y=6 2x+3y=17(用加减法)](/uploads/image/z/1614102-6-2.jpg?t=%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%842x-y%3D1+2y%2Bx%3D8%EF%BC%88%E4%BB%A3%E5%85%A5%E6%B3%95%EF%BC%89+5x%2B2y%3D7+16x%2B9y%3D12%28%E5%8A%A0%E5%87%8F%E6%B3%95%EF%BC%89+x-2y%3D3+2x-1%2F2y%3D6%EF%BC%88%E7%94%A8%E4%BB%A3%E5%85%A5%E6%B3%95%EF%BC%894x-3y%3D-1+4x%2B5y%3D7+%EF%BC%88%E7%94%A8%E5%8A%A0%E5%87%8F%E6%B3%95%EF%BC%89+3x-2y%3D6+2x%2B3y%3D17%EF%BC%88%E7%94%A8%E5%8A%A0%E5%87%8F%E6%B3%95%EF%BC%89)
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解方程组2x-y=1 2y+x=8(代入法) 5x+2y=7 16x+9y=12(加减法) x-2y=3 2x-1/2y=6(用代入法)4x-3y=-1 4x+5y=7 (用加减法) 3x-2y=6 2x+3y=17(用加减法)
解方程组2x-y=1 2y+x=8(代入法) 5x+2y=7 16x+9y=12(加减法) x-2y=3 2x-1/2y=6(用代入法)
4x-3y=-1 4x+5y=7 (用加减法) 3x-2y=6 2x+3y=17(用加减法)
解方程组2x-y=1 2y+x=8(代入法) 5x+2y=7 16x+9y=12(加减法) x-2y=3 2x-1/2y=6(用代入法)4x-3y=-1 4x+5y=7 (用加减法) 3x-2y=6 2x+3y=17(用加减法)
2x-y=1 2y+x=8(代入法)
2x-y=1 (1)
2y+x=8 (2)
由(1)式得 y=2x-1 (3)
代入(2)式得:
2(2x-1)+x=8
4x-2+x=8
5x=10
x=2 代入(3)得
y=3
5x+2y=7 (1) 16x+9y=12 (2)(加减法)
(1)×9-(2)×2得:
45x-32x=63-24
13x=39
x=3
(1)×16-(2)×5得:
32y-45y=102-60
-13y=42
y=-4
x-2y=3 (1) 2x-1/2y=6 (2)(用代入法)
由(1)得 x=2y+3 (3)
代入(2)得:
2(2y+3)-1/2y=6
4y+6-1/2y=6
y=0 代入(3)得:
x=3
4x-3y=-1 (1) 4x+5y=7 (2)(用加减法)
(2)-(1)得:
8y=8
y=1 代入(1)
4x-3=-1
x=1/2
3x-2y=6 (1) 2x+3y=17 (2)(用加减法)
(1)×3+(2)×2 得:
9x+4x=18+34
13x=52
x=4
(2)×3-(1)×2 得:
9y+4y=51-12
13y=39
y=3