x/(x-3)-2=m/(x-3)[x-2(x-3)]/(x-3)=m/(x-3)(-x+6)/(x-3)=m/(x-3)-x+6=mx=6-m有正数解，x>06-m>0m<6又分母不等于0，x不等于3所以6-m不等于3，m不等于3所以m<6且m≠3
