⚠ x^{-2/3} is read as x^(-2/3): use ^(...) to group an exponent, use * to multiply

Let's reduce: $x^{-\frac{2}{3}}$

ⓘ A negative exponent moves the power to the other side of the fraction bar, for a nonzero base: $x^{-\frac{2}{3}}$ = $\frac{1}{x^{\frac{2}{3}}}$

▶Simplified form:   $\frac{1}{x^{\frac{2}{3}}}$