7m/(m-3)=[7(m-3)+21]/(m-3)=7+21/(m-3)∴m-3是21的约数∴m=2,4,6,0,10,24
7m/(m-3)=[7(m-3)+21]/(m-3)=7+21/(m-3)∴m-3是21的约数∴m=2,4,6,0,10,24正确
