3³√24+³√375

3³√24+³√375

$$3\sqrt[3]{8*3}+\sqrt[3]{5*5*5*3}\\\\
=3*2\sqrt[3]{3}+5\sqrt[3]{3}\\\\
=6\sqrt[3]{3}+5\sqrt[3]{3}\\\\
=11\sqrt[3]{3}\\\\$$

check

$${\mathtt{3}}{\mathtt{\,\times\,}}{\sqrt[{{\mathtt{{\mathtt{3}}}}}]{{\mathtt{24}}}}{\mathtt{\,\small\textbf+\,}}{\sqrt[{{\mathtt{{\mathtt{3}}}}}]{{\mathtt{375}}}} = {\mathtt{15.864\: \!745\: \!273\: \!381\: \!492\: \!2}}$$

$${\mathtt{11}}{\mathtt{\,\times\,}}{\sqrt[{{\mathtt{{\mathtt{3}}}}}]{{\mathtt{3}}}} = {\mathtt{15.864\: \!745\: \!273\: \!381\: \!492\: \!2}}$$

Good, they are the same   

See what you can do with a bit of reading on surds. :) You'd be surprized about how fast you will pick it up. Might be something good on youtube as well. I think Kahn Acadamy would be the first stop.