20x+3y+2z=8239x+5y+3z=152要求的是2x+2y+2z

x/2=y/3=z/5 x+3y-z/x-3y+z 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. x+2y+3z=20,x+3y+5z=31,求x+y+z的值 x+y-z=5,2x+3y+z=10,x-2y-z=20求方程组 x+y-z=5 2x+3y+z=10 x-2y-z=20 速解, 2分之x=3分之y=5分之z x+y+z=20 求x,y,z (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 求{x+y-z=5；2x+3y+z=10；x-2y-z=20中x、y、z的值, 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 3X+2y+z=20 x+y+z=10 Y=3X x+y=5 2x+3y-z=9 x-y+z=4 已知x/y+z=y/x+z=z/x+y,分式(x+2y+3z)/(2x+5y-2c)有意义时的值 1.（x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2) x+y+z=35 2x-y=5 y/3=z/2 求x,y,z (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊