x\2=y\3=z\4 x+y+z=18解方程组 需要全部过程

x+y/2=z+x/3=y+z/4 x+y+z=27 x+2y=3x+2z=4y+z 求x:y:z 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) 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, 如果x/2=y/3=z/4,且x+y+z=18,那么x+y-z=? x：y：z=3:4:7 2x-3y+z=18 求：3x-2y+z 解方程组x-4y+z=-3,2x+y-z=18,x-y-z=7. x-4y+z=-3 2x-y+z=18 x-y-z=12 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 X+2Y+3Z=18 X+4Y+3Z=24 Y=? (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 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=? x-4y+z=-302x+y-z=18x--y-z=7 (x+y-z)(x-y+z)=