# How do you express b^-15 as a positive exponent?

$\frac{1}{b} ^ 15$
A bit deeper, using the power property of exponents we know that ${b}^{-} 15 = {\left({b}^{15}\right)}^{-} 1$ and since ${x}^{-} 1$ means $\frac{1}{x}$, if we substitute ${b}^{15}$ for x then we have our answer.