Answer
$256$
Work Step by Step
Recall the basic exponent property (pg. 360):
$a^ma^n=a^{m+n}$
Applying this property, we get:
$\left(64^{\frac{2}{3}}\right)\left(64^{\frac{2}{3}}\right)=64^{\frac{2}{3}+\frac{2}{3}}=64^{\frac{4}{3}}$
Since $4^3=64$, then:
$64^{\frac{4}{3}}=(4^3)^{\frac{4}{3}}$
Next, recall the basic exponent property (pg. 360):
$(a^m)^n=a^{mn}$
Thus, $\left(4^3\right)^{\frac{4}{3}}$ simplifies to:
$=4^{\frac{4\cdot 3}{3}}$
$=4^{\frac{12}{3}}$
$=4^4$
$=256$
