Perform indicated operation and simplify

Hello, Hapa!

It's impossible to read what you've typed.
But I'll take a guess at what you meant . . .

Quote:

Simplify: . $3\sqrt[4]{32a^5} - a\sqrt[4]{162a}$

I'll simplify those radicals separately . . .

. . $\sqrt[4]{32a^5} \:=\:\sqrt[4]{16a^4\cdot2a} \:=\:\sqrt[4]{16a^4}\cdot\sqrt[4]{2a} \;=\;2a\sqrt[4]{2a}$

. . $\sqrt[4]{162a} \:=\:\sqrt[4]{81\cdot2a} \:=\:\sqrt[4]{81}\sqrt[4]{2a} \:=\:3\sqrt[4]{2a}$

The problem becomes: . $3\left(2a\sqrt[4]{2a}\right) - a\left(3\sqrt[4]{2a}\right)$

. . . . . . . . . . . . . . . $= \;6a\sqrt[4]{2a} - 3a\sqrt[4]{2a}$

. . . . . . . . . . . . . . . $= \;3a\sqrt[4]{2a}$