## Elementary Algebra

$\dfrac{1}{a^{10}}$
Using the laws of exponents, the given expression, $a^{-4}a^{-6} ,$ is equivalent to \begin{array}{l}\require{cancel} a^{-4+(-6)} \\\\= a^{-4-6} \\\\= a^{-10} \\\\= \dfrac{1}{a^{10}} .\end{array} For more complicated problems, it is helpful to remember that you can flip the location of numbers with negative exponents. In other words, you can move numbers with a negative exponent that are in the numerator to the denominator, and you can move numbers with a negative exponent in the denominator to the numerator.