Вычислите 1,8 * (5/6 - 0,7)- 1 4/5 : 7,5

Здравствуйте!
$1.8 \times( \frac{5}{6} - 0.7) - 1 \frac{4}{5} \div 7.5 = 1\frac{8}{10} \times ( \frac{5}{6} - \frac{7}{10} ) - \frac{9}{5} \div 7 \frac{5}{10} = \frac{18}{10} \times ( \frac{25}{30} - \frac{21}{30} ) - \frac{9}{5} \times \frac{10}{75} = \frac{18 \times 4}{10 \times 30} - \frac{9 \times 10}{5 \times 75} = \frac{3 \times 2}{5 \times 5} - \frac{3 \times 2}{25} = \frac{6}{25} - \frac{6}{25} = 0$