已知X/Y=2,X/Z=4,Z=1,求代数式X+Y+Z的和除以X-Y+Z的值
已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/(除以)x-y+z的值.
已知x+y-1的绝对值+x+2y+z的和的平方+x-3z的绝对值=0,求代数式x-y+z的值.
已知x除以2=y除以3=z除以4,且x≠0,求x+y+z除以x-2y+3z的值,
已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/
已知x、y、z满足方程组:x+y-z=6;y+z-x=2;z+x-y=0 求x、y、z的值
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
已知X、Y、Z满足2X-Y+4Z=8(1);X-2Y-Z=7(2)求X-Y-Z的值
1 已知想x,y,z满足2x-y+4z=8,x-2y-z=7,求x-y+z的值
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
已知:(x+y-z)/z=(x-y+z)/y+(y+z-x)/x,且xyz≠0,求代数式[(x+y)(y+z)(x+z)
x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y----
已知2x=3y=4z求2x-y+z分之x+y+z的值