I am confused by this, pleas explain the answer but also how to do problems like these.

SOLUTION
We want to simplify
[tex]\sqrt{48n^5}[/tex]This becomes
[tex]\begin{gathered} \sqrt{48n^5} \\ =(48n^5)^{\frac{1}{5}} \\ =48^{\frac{1}{5}}\times n^{5\times\frac{1}{5}} \\ =48^{\frac{1}{5}}\times n^{\frac{5}{5}} \\ =48^{\frac{1}{5}}n \\ =(\sqrt[5]{48})n \end{gathered}[/tex]Hence the answer is
[tex](\sqrt[5]{48})n[/tex]