a)
[tex] - 2 \times ( - 3) + 2 \times ( - 4) - 28 \div ( - 7) = 6 - 8 + 4 = - 2 + 4 = 2[/tex]
b)
[tex]( - 0.1 + \frac{1}{5} ) \div ( \frac{3}{4} + ( - 3.4)) = ( - \frac{1}{10} + \frac{2}{10} ) \div ( \frac{75}{100} - \frac{17}{5} ) = \frac{1}{10} \div ( \frac{75}{100} - \frac{340}{100}) = \frac{1}{10} \div ( - \frac{265}{100} ) = \frac{1}{10} \times ( - \frac{100}{265} ) = - \frac{10}{265} = - \frac{2}{53} [/tex]
