2x-y=8 3y+z=-7 4z-x=-7 这个方程组怎么解?在今天下午1：30分之前有加分

(4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 已知关于x y z的方程组2x-3y+5z=7 x+2y-3z=8,则4x+y-z= x+y/2=z+x/3=y+z/4 x+y+z=27 三元一次方程组2x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4z=262x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4z=26 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 x+2y=3x+2z=4y+z 求x:y:z (x*x+2)(y*y+4)(z*z+8)=64xyz,求x,y,z (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 3x+2y+z=3 2x=4-3z=-8 x+y-2z=-4 2x+y+3z=7 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 解下列三元一次方程组:(1)x-z=4,x+y-z=-1,2y-z=1 (2)3x+4z=7,2x+3y+z=9,x-y+z=8 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z 解方程：{2x+3y+z=7,x+y+z=4,3x+y-z=-4{2x+3y+z=7,x+y+z=4,3x+y-z=-4要过程 x+Y+Z=1 X+3Y+7Z=-1 X+5Y+8Z=2x+Y+Z=1X+3Y+7Z=-1X+5Y+8Z=2 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,