5 since there is no integer k such that 5 = 0 · k.1. a) Yes. 4 | 72 since 72 = 4 · 18.
b) No. 24 is not a multiple of 48 since there is no integer k such that 24 = 48 · k.
c) No. 05 since there is no integer k such that 5 = 0 · k.
d) Yes. -3 is a factor of 9 since 9 = (-3) · (-3).