Factorization $a^x-1 | (a^x)^k - 1$

Question

$a^x-1 | (a^x)^k - 1$

Is this expression true, and if yes how can I prove it?

Answer 1

Hint: recognize the pattern $\frac{q^n-1}{q-1}$, which is the sum of the first ${n-1}$ terms of a geometric sequence.