Help with Exponent Expression

I am going to post the entire problem & its solution. I am confused with one particular step in working towards the solution.

$\displaystyle (2x^3+4)^{-6}(2x^3+4)^4=(2x^3+4)^{-6+4} =(2x^3+4)^{-2} = \frac{1}{(2x^3+4)^2}$

How are the **two **"$\displaystyle (2x^3+4)$" combined to form one $\displaystyle (2x^3+4)$? Is it because they both have the same base therefore just add the exponents together? Im thinking that must be correct, otherwise I wouldnt be adding these exponents to begin with.