The top and bottom of the fraction both contain negative exponents. Since $c^{-3}$ on the bottom has a negative exponent, it is moved to the top of the fraction (numerator). Since the $d^{-3}$ on the top of the fraction has a negative exponent, it is moved to the bottom of the fraction (denominator).
$$\frac{d^{-3}} {c^{-3}}$$
to
$$\frac{c^3} {d^3}$$
Any explanation why does this happen?
[Math] variable with negative exponent in the denominator moved to nominator and vice versa
algebra-precalculusexponentiation
Best Answer
One of the laws of exponents is $a^{-b}=\frac 1{a^b}$. So the $d^{-3}$ in the numerator is equal to $\frac 1{d^3}$ and $\frac 1{c^{-3}}=c^3$. Putting them together gives what you are asking about.