Answer:
![\sqrt[6]{2}](https://img.qammunity.org/2017/formulas/mathematics/high-school/a1fiiqdisaxfxv66qxr0kwesdoia7c5baf.png)
Step-by-step explanation: The easiest way to do this problem is to factor 72 as 2 · 36 then recognise 36 as a perfect square, 6 · 6.
There is no need to factor further because the 6's pair up. So a 6 comes out of the radical leaving a 2 inside and our answer is
.
As you make your factor tree, always be on the lookout for perfect squares such as 36.
I have shown my work in the image attached.