Answer:
The value remains under the radical is 3.
Explanation:
Given : When 9 Superscript two-thirds is written in simplest radical form.
To find : Which value remains under the radical?
Solution :
The expression given 9 Superscript two-thirds is written as,

We re-write the expression as,

![9^{(2)/(3)}=\sqrt[3]{9^2}](https://img.qammunity.org/2020/formulas/mathematics/high-school/ernnaj1pn45f7d6ijnrmjt3m9c3f3lqm9v.png)
![9^{(2)/(3)}=\sqrt[3]{81}](https://img.qammunity.org/2020/formulas/mathematics/high-school/zwt00w6ocqy4vctvssyaxlyvea9qzimttz.png)
![9^{(2)/(3)}=\sqrt[3]{3* 3* 3* 3}](https://img.qammunity.org/2020/formulas/mathematics/high-school/lmzuuyv63vihaoz7dhxn3enbzhxrcfasju.png)
![9^{(2)/(3)}=3\sqrt[3]{3}](https://img.qammunity.org/2020/formulas/mathematics/high-school/rgfaob80sqh0vn0ixwohxvaxea4uvl6e9l.png)
Therefore, the value remains under the radical is 3.