求{5x-3y+z= -2 ,5x+2y-4x=3 ,-5x+y-z=2}方程组的解由1+2,得即由2+3,得把xx=XX代入1,得把xx=xx,xx=xx代入1,得所以,原方程的解是

设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 x+y+z=35 2x-y=5 y/3=z/2 求x,y,z 3x=4y 2y=5z 试求x:y:z 已知x:：y：z=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. 3x-y=-7,y+2z=2,2x-2z=-5 求x,y,z 2x+Y+3z=23,x+4y+5z=36,求X+2Y+3z~ 已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z x+y-z=5,2x+3y+z=10,x-2y-z=20求方程组 2x+y-z=3 5x+3y-z=10 求x+y+z= 已知x:y:z=1:3:5,求（2x+3y-z)/(x+y-2z)的值 x:y:z=2:1:5,2x+3y-z=18,求x,y,z,值 若x/3=y/4=z/5,求x+y+z/3x-2y+z的值. x/3=y/4=z/5,求x+y+z/3x-2y+z的值, x+2y+3z=20,x+3y+5z=31,求x+y+z的值 2分之x=3分之y=5分之z x+y+z=20 求x,y,z 已知X:Y:Z=3:4:5,求4X+3Y-2Z/X+Y+Z的值 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值