3(x+y)-4(x-y)=4 x+2y+3z=5x+y/2+x-y/6=1 2x+3y+6z=95x+3y+9z=15 3(x+y)-4(x-y)=4 x+2y+3z=5 两式一道!(二元一次方程组)x+y/2+x-y/6=1 2x+3y+6z=9 5x+3y+9z=15 (三元一次方程组)

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3(x+y)-4(x-y)=4x+2y+3z=5x+y/2+x-y/6=12x+3y+6z=95x+3y+9z=153(x+y)-4(x-y)=4x+2y+3z=5两式一道!(二元一次方程组)x+y/

3(x+y)-4(x-y)=4 x+2y+3z=5x+y/2+x-y/6=1 2x+3y+6z=95x+3y+9z=15 3(x+y)-4(x-y)=4 x+2y+3z=5 两式一道!(二元一次方程组)x+y/2+x-y/6=1 2x+3y+6z=9 5x+3y+9z=15 (三元一次方程组)
3(x+y)-4(x-y)=4 x+2y+3z=5
x+y/2+x-y/6=1 2x+3y+6z=9
5x+3y+9z=15
3(x+y)-4(x-y)=4 x+2y+3z=5 两式一道!(二元一次方程组)
x+y/2+x-y/6=1 2x+3y+6z=9 5x+3y+9z=15 (三元一次方程组)

3(x+y)-4(x-y)=4 x+2y+3z=5x+y/2+x-y/6=1 2x+3y+6z=95x+3y+9z=15 3(x+y)-4(x-y)=4 x+2y+3z=5 两式一道!(二元一次方程组)x+y/2+x-y/6=1 2x+3y+6z=9 5x+3y+9z=15 (三元一次方程组)
3(x+y)-4(x-y)=4x+2y+3z=5 .1
x+y/2+x-y/6=1 2x+3y+6z=9 .2
5x+3y+9z=15 .3
1式*2-2式得:6X+Y=1
1式+2式-3式得:X+2Y=-1
3式-2式得:X+Z=2
6X+Y=1
X+2Y=-1
X+Z=2
X=3/11.
Y=-7/11
Z=19/11

∵3(x+y)-4(x-y)=4即:3x+3y-4x+4y=7y-x=4⑴
x+2y+3z=5⑵
x+y/2+x-y/6=1即:3(x+y)+x-y=6=4x+2y=6⑶
2x+3y+6z=9 ⑷
5x+3y+9z=15 ⑸
∴由⑴乘以4加⑶得
28y-4x+4x+2y=16+6=2...

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∵3(x+y)-4(x-y)=4即:3x+3y-4x+4y=7y-x=4⑴
x+2y+3z=5⑵
x+y/2+x-y/6=1即:3(x+y)+x-y=6=4x+2y=6⑶
2x+3y+6z=9 ⑷
5x+3y+9z=15 ⑸
∴由⑴乘以4加⑶得
28y-4x+4x+2y=16+6=22
∴y=11/15 x=17/15
把y=11/15 x=17/15代入⑷得:
在=68/15
什么题啊?已知给得太多了

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