If $a$ is an integer and $b$ is a fourth power of an integer such that $ab$ is the fourth power of an integer, explain why $a$ is also a fourth power of an integer.
Show that $a$ is the fourth power of an integer if: $b^4$ $(ab)^4$
If $a$ is an integer and $b$ is a fourth power of an integer such that $ab$ is the fourth power of an integer, explain why $a$ is also a fourth power of an integer.
Show that $a$ is the fourth power of an integer if: $b^4$ $(ab)^4$
HINT: What can you say about the exponents in the prime decomposition of a fourth power?