x+y+z=77 x-5=y y=4z

(x+y-z)(x-y+z)= x+y+z=77 y+5=z 4x=z三元一次方程组 X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) x+y+z=77 x-5=y y=4z (x+y):(y+z):(z+x)=3:4:5 3x+y-z=-4已知(x+y):(y+z):(z+x)=3:4:5 ；3x+y-z=-4求x y 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=4x-5y=y-x+6z,xyz不等0,x:y:z=? (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 已知x:4=y:5=z:6.则x:y:z= (x+y):(y+z)= (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 x+y/2=z+x/3=y+z/4 x+y+z=27 x-4y+z=-302x+y-z=18x--y-z=7