# How do you divide ((b^4)/(b^7))^-5?

Jul 19, 2015

I found: ${b}^{15}$

#### Explanation:

You can start inside the bracket by remembering that: ${a}^{b} / {a}^{c} = {a}^{b - c}$;
so you get:
${\left({b}^{4 - 7}\right)}^{-} 5 =$
$= {\left({b}^{-} 3\right)}^{-} 5 =$
Now you can use the fact that ${\left({a}^{b}\right)}^{c} = {a}^{b \cdot c}$;
so you get:
${b}^{- 3 \cdot - 5} = {b}^{15}$