Question

(21² – 15²)^2/3 is equal to ________.

Answer 1

$$\begin{gathered} {\left({21}^2-{15}^2\right)}^{\frac{2}{3}}={\left(441-225\right)}^{\frac{2}{3}} \\ ={\left(216\right)}^{\frac{2}{3}} \\ ={\left(6^3\right)}^{\frac{2}{3}} \\ ={\left(6\right)}^{3\times \frac{2}{3}} \\ ={\left(6\right)}^2 \\ =36 \end{gathered}$$

Hence, (21² – 15²)^2/3 is equal to 36.