## Algebra 1

$a^{-4}\times a^{4}=1$
$a^{?}\times a^{4}=1$ The zero as an exponent rule states that for every nonzero number $a$, $a^0=1$. Therefore, $a^{?}\times a^{4}=a^0$ To multiply powers with the same base, we add the exponents. When we add $4$ and the first exponent, we must get $0$. The only way this is true is if the first exponent is $-4$ because $4+(-4)=0$. Therefore, $a^{-4}\times a^{4}=a^0$ We rewrite the equation in its original form: $a^{-4}\times a^{4}=1$