(2) 5分之x+2分之y=6分之5,x+y=3 6x-7y=--2.5x-2y=-0.9三元一次方程组(1)x+y+z=1,x-y+z=3,x+y-z=-1 （1）x-y=3,x+2y+z=8,2x-y-3z=1 (3) 3(2x-y)+4(x-2y)=87,2(3x-y)-3(x-y)=82麻烦再接解道题3(2x-y)+4(x-2y)=87，2(3x-y)-3(x-y)=82解三元一次方程组(1)x+y+z=1,x-y+z=3,x+y-z=-1 （1）x-y=3,x+2y+z=8,2x-y-3z=1
问题描述：
(2) 5分之x+2分之y=6分之5,x+y=3 6x-7y=--2.5x-2y=-0.9
三元一次方程组(1)x+y+z=1,x-y+z=3,x+y-z=-1 （1）x-y=3,x+2y+z=8,2x-y-3z=1 (3) 3(2x-y)+4(x-2y)=87,2(3x-y)-3(x-y)=82
麻烦再接解道题3(2x-y)+4(x-2y)=87，2(3x-y)-3(x-y)=82解三元一次方程组(1)x+y+z=1,x-y+z=3,x+y-z=-1 （1）x-y=3,x+2y+z=8,2x-y-3z=1
答
X=2 Y=-1 Z= 0
X=4 Y=1 Z=2
X=23 Y=13
答
先消去X或Y，就可解的Y或X，下面的同理
1 X=2 Y=-1 Z= 0
2 X=4 Y=1 Z=2
3 X=23 Y=13
答
1 X=2 Y=-1 Z= 0
2 X=4 Y=1 Z=2
3 X=23 Y=13
答
1X=2 Y=-1 Z= 0
2 X=4 Y=1 Z=2
3 X=23 Y=13
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1x=2y=1z=0
2x=4y=1z=2
3x=23y=13