Question

never done these help?

Answer 1

I'll get you started
\[\Large \frac{1}{a^{-3}} + \frac{1}{a^5}\]
\[\Large \frac{a^3}{1} + \frac{1}{a^5}\]
\[\Large \frac{a^3{\color{red}{*a^5}}}{1{\color{red}{*a^5}}} + \frac{1}{a^5}\]
\[\Large \frac{a^3*a^5}{a^5} + \frac{1}{a^5}\]
and I'll let you finish up from here

Notice in step 3 I multiplied top and bottom of the first fraction by a^5 to get the denominators the same