若|x-2|+|y+3|+|z-5|=0,计算:（1）x,y,z的值； （2）求|x|+|y|+|z|的值.

若xyz≠0且4(x/z)-5(y/z)=-2,(x/z)+4(y/z)=3,求x:y:z 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 1.若3x-2y+z=2;3x+2y+5z=4,求x+22.若x-3y+z=0;3x-3y-4z=0,求x:y:z 若|x-2|+|y+3|+|z-5|=0,求|x|+|y|+|z|的值. 三元一次方程组题目x+y-z=11 y+z-x=5 x-y+z=1x+y=4 y+z=3 x+z=5若已知x-3y+2z=0 2x+3y-8z=0, 且xyz≠0,则x:y:z= 若x+2y-9z=0,x-2y+5z=0,(x.y.z≠=0)求2x平方+3y平方+7z平方/x平方-4y平方+4z平方 已知z、y、z同时满足x+3y-5z=0,2x-y-3z=0,求x:y:z 若X:Y:Z=5:6:7那么(Y-X):(Y+Z)和(X+2Y+3Z):(3X+2Y+Z) 若2x+5y+4z=0 ,3x+y=0；则x+y-z=? 三元一次方程：x+y-z=0 x+2y+z=13 2x-3y+2z=5x+y-z=0 x+2y+z=13 2x-3y+2z=5 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：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 若方程组2x+3y-z=0,x-3y-z=0,则x：y：z=? 若方程组：x+y-2z=0,3x+y-z=0,则x：y：z= x+y-z=0 x+2y-z=3 2x-3y+2z=5 x+y-z=0 2x-3y+2z=5 x+2y-z=3