[tex] \sqrt[4]{ \frac{16}{81} } + {13}^{0} \times {3}^{ - 2} = \frac{2}{3} + 1 \times ( \frac{1}{3} ) {}^{2} = 1 \frac{2}{3} \times \frac{1}{9} = \frac{5}{3} \times \frac{1}{9} = \frac{5}{27} [/tex]