I don't know how to do this Problem
(Properties of Rational Exponents; Algebra2)

3＾√375+3^√81:confused:

Here's one way. Assuming this is what you mean. What are you supposed to do? Simplify, I suppose?

3^{sqrt{375}}+3^{\sqrt{81}}

3^{\sqrt{15\cdot{25}}}+3^{9}

3^{5\sqrt{15}}+3^{9}

243^{\sqrt{15}}+243\cdot{3^{4}}

You can arrange it how you like by using various exponent laws.