(1)当9分之x是真分数时,(x=1~8),
(2)当9分之x是假分数时,(x≧9),
(3)当9分之x可以化成整数时,(x=9的倍数),
(4)当9分之x=1时,(x=1),
(5)当9分之x=0时,(x=0).