a)
[tex]2 \frac{1}{3} \times \frac{4}{7} + \frac{9}{5} \div 3 - \frac{1}{12} = \\ \\ = \frac{7}{3} \times \frac{4}{7} + \frac{9}{5} \times \frac{1}{3} - \frac{1}{12} = \\ \\ = \frac{4}{3} {}^{ {}^{)20} } + \frac{3}{5} {}^{ {}^{)12} } - \frac{1}{12} {}^{ {}^{)5} } = \\ \\ = \frac{80 + 36 - 5}{60} = \\ \\ = \frac{111}{60} = \\ \\ = \frac{37}{20} [/tex]
b)
[tex](( \frac{2}{3} ) {}^{ {}^{ {}^{5} } } ) {}^{ {}^{ {}^{ {}^{4} } } } \div ( \frac{2}{3} ) {}^{ {}^{ {}^{17} } } = \\ \\ = ( \frac{2}{3} ) {}^{ {}^{ {}^{5 \times 4} } } \div( \frac{2}{3} ) {}^{ {}^{ {}^{17} } } = \\ \\ = ( \frac{2}{3} ) {}^{ {}^{ {}^{20} } } \div ( \frac{2}{3} ) {}^{ {}^{ {}^{17} } } = \\ \\ = ( \frac{2}{3} ) {}^{ {}^{ {}^{20 - 17} } } = \\ \\ = ( \frac{2}{3} ) {}^{ {}^{ {}^{3} } } = \\ \\ = \frac{8}{27} [/tex]
