x/(x-3)-2-m/(x-3)=0 (x-m)/(x-3)-2=0 (x-m)-2(x-3)=0 x-m-2x+6=0 x=6-m >0 所以m<6
x/(x-3)-2-m/(x-3)=0 x-2(x-3)-m=0 -x+6-m=0 x=-m+6>0 x≠3 m<6 m≠3
