作业帮初一的三道二元一次方程!急用!① [ 2(x-y)]/3 - [x+y]/4=-16(x+y) - 4(2x-y)=16② [x+1]/5=[y-3]/23x+4y=32③ [3x+2y]/4=[2x+y]/5=[x-y+1]/6
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![初一的三道二元一次方程!急用!① [ 2(x-y)]/3 - [x+y]/4=-16(x+y) - 4(2x-y)=16② [x+1]/5=[y-3]/23x+4y=32③ [3x+2y]/4=[2x+y]/5=[x-y+1]/6](/uploads/image/z/8578228-4-8.jpg?t=%E5%88%9D%E4%B8%80%E7%9A%84%E4%B8%89%E9%81%93%E4%BA%8C%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%21%E6%80%A5%E7%94%A8%21%E2%91%A0+%5B+2%28x-y%29%5D%2F3+-+%5Bx%2By%5D%2F4%3D-16%28x%2By%29+-+4%282x-y%29%3D16%E2%91%A1+%5Bx%2B1%5D%2F5%3D%5By-3%5D%2F23x%2B4y%3D32%E2%91%A2+%5B3x%2B2y%5D%2F4%3D%5B2x%2By%5D%2F5%3D%5Bx-y%2B1%5D%2F6)
初一的三道二元一次方程!急用!① [ 2(x-y)]/3 - [x+y]/4=-16(x+y) - 4(2x-y)=16② [x+1]/5=[y-3]/23x+4y=32③ [3x+2y]/4=[2x+y]/5=[x-y+1]/6
初一的三道二元一次方程!急用!
① [ 2(x-y)]/3 - [x+y]/4=-1
6(x+y) - 4(2x-y)=16
② [x+1]/5=[y-3]/2
3x+4y=32
③ [3x+2y]/4=[2x+y]/5=[x-y+1]/6
初一的三道二元一次方程!急用!① [ 2(x-y)]/3 - [x+y]/4=-16(x+y) - 4(2x-y)=16② [x+1]/5=[y-3]/23x+4y=32③ [3x+2y]/4=[2x+y]/5=[x-y+1]/6
① [ 2(x-y)]/3 - [x+y]/4=-1 (1)
6(x+y) - 4(2x-y)=16 (2)
由（1）得
8(x-y)-3(x+y)=-12
5x-11y=-12 (3)
由（2）得
6x+6y-8x+4y=16
-2x+10y=16
x-5y=-8 (4)
解（3）（4）得
x=2
y=2
② [x+1]/5=[y-3]/2 (1)
3x+4y=32 (2)
由（1）得 2x+2=5y-15
2x-5y=-17
6x-15y=-51 （3）
(2)*2-(3)得 23y=115
y=5
把y=5代入（2） 得
x=4
∴x=4
y=5
③ [3x+2y]/4=[2x+y]/5 (1)
[3x+2y]/4=[x-y+1]/6 (2)
由（1）得 15x+10y=8x+4y
7x+6y=0 (3)
由（2）得 9x+6y=2x-2y+2
7x+8y=2 (4)
解（3）（4）得
x=-6/7
y=1