x+y+z=77 y+5=z 4x=z三元一次方程组

(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):(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)=? (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 X/4=Y/5=Z/7则x+y+z/z=? 一道数奥题,(x+y-z)²+(y+z-4)=-|z+x-5| x+y+z=77 x-5=y y=4z 解下列方程 三元一次方程一、 5x-3y+z=25x+2y-4z=3-5x+y-z=2二、x+y=-2x+z=13y+z=1三、x-y-z=-13x+5y+7z=114x-y+2z=-1第二题不用了 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 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)}=? fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 z=x^(y/z) 偏导数 {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1