x+y =7 y+z=9 x+z=8

(x+y-z)(x-y+z)= fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 若X/10=Y/8=Z/9则X+Y+Z/Y+Z=? X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z x+y+z=6,y+z+a=9,z+a+x=8,a+x+y=7 方程组 2x+y+z=7,x+2y+z=8,x+y+2z=9 快 X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 解方程组：{x(x+y+z)=6 {y(x+y+z)=9 {z(x+y+z)=10 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z x+y=8 y+z=12 x+z=10 x+y+z= x+y=8 y+z=12 x+z=10 x+y+z= x-4y+z=-302x+y-z=18x--y-z=7 x+y+z=14 7z=x+y+2 x+z=y