To make that negative exponent positive, we have to put it under a 1. It's already under a 1, but we have to put it under another 1! Like this: [tex] \frac{1}{ \frac{1}{ a^{5} } } [/tex]. That's like [tex] \frac{ \frac{1}{1} }{ \frac{1}{ a^{5} } } [/tex]. When we divide a fraction by a fraction, we bring up the bottom one and flip it to multiply to give us this expression: [tex] \frac{1}{1} * \frac{ a^{5} }{1} [/tex], which of course simplifies to just [tex] a^{5} [/tex]