已知4x-3y-6z=0, x+2y-7z=0所以y=2z x=3z所以(2x+3y+6z)/(x+5y+7z) =(6z+6z+6z)/(3z+10z+7z) =18z/20z =9/10
已知4x-3y-6z=0,x+2y-7z=0所以y=2zx=3z所以(2x+3y+6z)/(x+5y+7z)=(6z+6z+6z)/(3z+10z+7z)=18z/20z=9/10