(2x-3y+4z)(2x+3y-4z)=( )-( )

化简-(-3x-y+2z)-{-x+【4x-(x-y-z)-3x+2z} x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 数学--整式运算4(x-y+z)-2(x+y-z)-3(-x-y-z) 求化简(x+3y+2z)(x-3y+6z)(x+3y+4z-2z)(x-3y+4z+2z) 因式分解Z^2(x-y)-4(x-y)-3Z(y-z) 2x+z=10 x+y-z=4 3x-y-z=0 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 3x-y+z=4,2z+3y-z=12,x+y+z=6的解 x/2=y/3=z/4,则x+2y-z/z=? 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 设x,y.z为实数,2x.3y.4z是等比数列,1/x,1/y.1/z是等差数列,则(x/z)+(z/x)是多少? (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 12x^2y^3z-8x^3y^2z+4x^2y x+y=5 2x+3y-z=9 x-y+z=4 因式分解x^2(y-z)-4(y-z)-3x(x-y) 因式分解:z^2（x-y）-4（x-y）-3z（y-x）