Question

if a and b are positive integers, such that the greatest common factor of a^2b^2 and ab^3 is 45, then which of the following could b equal?
a)3
b)5
c)9
d)15
e)45

Answer 1

well look at a^2b^2 and ab^3
let's look at just the a parts of each terms
do you see any common factors among a^2 and a?