解三元一次方程组1、x+y-z=4 2x-y+z=5 x-3y+z=-2 2、y+2z=-2 3x+y-4z=1 2x-

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解三元一次方程组1、x+y-z=4 2x-y+z=5 x-3y+z=-2 2、y+2z=-2 3x+y-4z=1 2x-y+2z=8 3、x-2y+z=-1 x+y+z=2
x+2y+3z=-1

1.x+y-z=4 2x-y+z=5 x-3y+z=-2 (x+y-z)+(2x-y+z)=4+5 3x=9 x=3
(2x-y+z)-(x-3y+z)=5-(-2) x+2y=7 把x=3代入x+2y=7可得 3+2y=7 2y=4 y=2
把x=3,y=2代入x+y-z=4 可得 3+2-z=4 5-z=4 z=1
2.y+2z=-2 3x+y-4z=1 2x-y+2z=8 (y+2z=-2)×2可得2y+4z=-4 (3x+y-4z)+(2y+4z)=1-4
3x+3y=-3 x+y=-1 (x+y=-1)×2可得2x+2y=-2 (2x-y+2z)-(y+2z)+(2x+2y)=8-(-2)-2
4x=8 x=2 (2x-y+2z)-(y+2z)=8-(-2) 2x-2y=10 x-y=5 把x=2代入x-y=5 可得 2-y=5 y=-3
把y=-3代入y+2z=-2可得 -3+2z=-2 z=0.5
3、x-2y+z=-1 x+y+z=2 x+2y+3z=-1 (x-2y+z)-(x+y+z)=-1-2 -3y=-3 y=1 把y=1代入x-2y+z=-1 可得 x-2+z=-1 x+z=1 (x+2y+3z)-(x+z)=-1-1 2y-2z=-2 y-z=-1 把y=1代入y-z=-1 可得 1-z=-1 z=2 把y=1,z=2 代入x+y+z=2 可得 x+1+2=2 x=-1

解三元一次方程组x:y:z=1:2:3 x+y+z=36 解三元一次方程组：x+y+z=6,y-z=4,x-y-2z=3, 求解三元一次方程组：｛x+y/2=y+z/3=z+x/4 x+y+z=27 解三元一次方程组1、x+y-z=4 2x-y+z=5 x-3y+z=-2 2、y+2z=-2 3x+y-4z=1 2x- 解三元一次方程组 1.{2x-y+z=1,3x+y-2z=2,x+2y-z=3 2.{3x-y+z=4,2x+3y-z= 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 解三元一次方程组1)2x+y-3z=3,3x-y+2z=1,x-y-z=5 2)x:y=3:2,y:z=5:4,x+y+ 解三元一次方程组：(1)x+2y+3z=11x-y+4z=10x+3y+2z=2(2)x:y=3:5y:z=5:6x+y 解三元一次方程组 5x+2y-4z=1,3x-3y+2z=1,-2x+3y-2z=0 解三元一次方程组：5x+y+z=1(1) 2x-y+2z=1(2) x+5y-z=-4(3) 急解三元一次方程组 {3x-5y+6Z=4, 3x-2y+2Z=3, -3x-3y+5z=-1 解三元一次方程组：{3x-5y+2z=1 {4x+5y-z=5 {x-5y+3z=-2