b)
[tex]( \frac{3}{9} + {( \frac{1}{3}) }^{2} ) \times \frac{15}{10} [/tex]
[tex]( \frac{3}{9} + \frac{ {1}^{2} }{ {3}^{2} } ) \times \frac{15}{10} [/tex]
[tex]( \frac{3}{9} + \frac{1}{9} ) \times \frac{15}{10} [/tex]
[tex] \frac{4}{9} \times \frac{15}{10} = \frac{2}{3} \times \frac{5}{5} = \frac{2}{3} \times 1 = \frac{2}{3}[/tex]
c)
[tex] \frac{83 - 8}{90} \div 2 \frac{3}{9} \times (1 + \frac{1}{2} \times \frac{1}{3} )[/tex]
[tex] \frac{75}{90} \div \frac{2 \times 9 + 3}{9} \times (1 + \frac{1}{2 \times 3} )[/tex]
[tex]\frac{5}{6} \div \frac{21}{9} \times (1 + \frac{1}{6} )[/tex]
[tex]\frac{5}{6} \times \frac{9}{21} \times ( \frac{6}{6} + \frac{1}{6} ) = \frac{5}{6} \times \frac{9}{21} \times \frac{7}{6} = \frac{5}{2} \times \frac{1}{3} \times \frac{1}{2} = \frac{5}{12} [/tex]