x-y-z=3① 2x+y-5z=18② 二分之一x-六分之一y+三分之一z=二分之一③ 解三元一次方程组 急 急 急

①5x-4y+4z=132x+7y-3z=193x+2y-z=18②y=2x-75x+3y+2z=23x-4z=4 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/2=y/3=z/5 x+3y-z/x-3y+z ①3x-4y+z=14x+5y+2z=172x+2y-z=3② x:y=3:2y:z=5:4x+y+z=66 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 解三元一次方程,①{x+y-z=0{ x+2y+z=13{2x-3y+2z=5②｛x+y-z=11｛y+z-x=5｛z+x-y=1③｛x+y=1｛y+z=6｛z+x=3 方程组 (1) x+2y-3z=12 x-3y+2z= - 13 x-y-z=0 (2) x+ y=z 5x-y+z=18 2x+5y+3z= -1 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) ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z-6=0③x/3=y/2 y/4=z/5 x+y+z=60三元一次方程 解方程组x+y/2=z+x/3=y+z/4①x+y+z=27② 三元一次方程求解：①x+2z=3,2x+y=2,2y+z=7.②x+y+z=2,3x-y-4z=5,2x+3y-2z=0. 已知x,y,z均不为0,且满足方程组{x+y-z=0,①2x-y-5z=0.②试求(2x+y+3z)/(3x-y-z)值. x:y:z=2:1:5,2x+3y-z=18,求x,y,z,值 2y+z=3y ① ,x+3y-z=8,② x+y+2z=13③ 求x,y,z 若2分之x+y=3分之y+z=5分之x+z 且x+y+z=18 求x,y,z的值 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? ①X+Y+Z=111②Y:X=3:2③Y:Z=5:4求x,y,z急～