2x-3y+5z与-3x+5y+z之和要加上多少才会等于5x-6y+4z?

2x-3y+5z与-3x+5y+z之和要加上多少才会等于5x-6y+4z? 2(x+y-z)-3(x-y+z)-5(x+y-z)+6(x-y+z) 计算 x/2=y/3=z/5 x+3y-z/x-3y+z 1.（x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2) 因式分解：25x y^2 z^2 (x+y-z)-30xyz(z-x-y)^2+5x y z^3 (z-x-y) 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. x+y+z=2 x-3y+2z=1 2x+2y+z+5 要具体步骤.. (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 x+2y+3z=23 y-z=5 x+2z=10 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 已知XYZ为三个非负有理数,且满足3X+2Y+Z=5,X+Y-Z=2,S=2X+Y-Z.则S的最大值与最小值之和是多少 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 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x+y+z=35 2x-y=5 y/3=z/2 求x,y,z 已知z、y、z同时满足x+3y-5z=0,2x-y-3z=0,求x:y:z x+y=5 2x+3y-z=9 x-y+z=4