3x+2y+z=3 2x=4-3z=-8 x+y-2z=-4 2x+y+3z=7

x+y/2=z+x/3=y+z/4 x+y+z=27 x+2y=3x+2z=4y+z 求x:y:z (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 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 2x+z=10 x+y-z=4 3x-y-z=0 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 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x:y:z=3:4:5 2x-3y+2z=8 x-y-2z=? 三元一次方程 X+Y+Z=6 2X+3Y-Z=4 3X-Y+Z=8 x+y+z=-1 4x-2y+3z=5 y-z=8-2x 2x+3y+z=8 4x-y-z=10 x+2y-z=1 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 x/2=y/3=z/4,则x+2y-z/z=? 3x-y+z=4,2z+3y-z=12,x+y+z=6的解 已知关于x y z的方程组2x-3y+5z=7 x+2y-3z=8,则4x+y-z=