已知20(x+2y)=15(y+3Z)=12(z+5x),则x:y
已知20(x+2y)=15(y+3Z)=12(z+5x),则x:y
已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=?
已知x+y=3,y+z=4,x+z=5,则x+y+z等于( )
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
已知x-y+z=0,3x+y-5z=0,则x+y+z/x+2y-3z=?
已知x+y-7z=0 x-2y+5z=0(xyz不等于0),求x+2y-z/y-2x+12z
已知x-y+z=0.3x+y-5z=0,则x+y+z/x+2y-3z=_______
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: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3x-2y-5z=0,2x-5y+4z=0,且x,y,z都不为0,求(3x*x+y*y+4z*z)/(5x*x+y*
已知2x+3y-4z=7 3x-2y+z=3 x+5y+9z=20 则 x+y+z= 若x :y :z=2 :3 :7
thank you已知x+3y+5z=0,2x+3y+z=0 且x、y、z.都不是0,则(2y-z)(2y+z)除以z的