let p1^a1.p2^a2 ... pn^an be the prime decomposition of a, and

q1^b1.q2^b2. ... qm^bm be the prime decomposition of b.

That a^3|b^2, means that there is some qi which is equal to pj for

each of the pj's in the prime factorisation of a.

Also pj occurs with multiplicity 3aj in the prime decomposition of a^3, and

with multiplicity 2bi in the prime decomposition of b^2.

Hence we must have 2bi>=3aj, or (2/3)bi>=aj which means that bi>aj.

That is all the common primes in the prime decomposition of a and b

occur with greater multiplicity in b than in a which implies that a|b.

RonL