Вычислите:
а) $0,8 + (-\frac{5}{6})$;
б) $-\frac{1}{50} + 1,37$;
в) $-7,11 - \frac{1}{2}$;
г) $\frac{2}{3} - 0,8$;
д) $-\frac{2}{7} * 1,4$;
е) $-0,24 * (-\frac{3}{16})$;
ж) $4,2 : (-\frac{6}{7})$;
з) $0,16 : 2\frac{2}{5}$;
и) $3\frac{1}{5} : 0,64$.
$0,8 + (-\frac{5}{6}) = \frac{8}{10} + (-\frac{5}{6}) = \frac{4}{5} + (-\frac{5}{6}) = \frac{24 - 25}{30} = -\frac{1}{30}$
$-\frac{1}{50} + 1,37 = -\frac{1}{50} + \frac{137}{100} = \frac{-2 + 137}{100} = \frac{135}{100} = 1,35$
$-7,11 - \frac{1}{2} = -7,11 - 0,5 = -7,61$
$\frac{2}{3} - 0,8 = \frac{2}{3} - \frac{8}{10} = \frac{2}{3} - \frac{4}{5} = \frac{10 - 12}{15} = -\frac{2}{15}$
$-\frac{2}{7} * 1,4 = -\frac{2}{7} * \frac{14}{10} = -\frac{2}{7} * \frac{7}{5} = -\frac{2}{5}$
$-0,24 * (-\frac{3}{16}) = \frac{24}{100} * \frac{3}{16} = \frac{3}{100} * \frac{3}{2} = \frac{9}{200}$
$4,2 : (-\frac{6}{7}) = \frac{42}{10} * (-\frac{7}{6}) = \frac{21}{5} * (-\frac{7}{6}) = -\frac{7 * 7}{5 * 2} = -\frac{49}{10} = -4,9$
$0,16 : 2\frac{2}{5} = \frac{16}{100} : \frac{12}{5} = \frac{4}{25} * \frac{5}{12} = \frac{1}{5} * \frac{1}{3} = \frac{1}{15}$
$3\frac{1}{5} : 0,64 = \frac{16}{5} : \frac{64}{100} = \frac{16}{5} : \frac{64}{100} = \frac{16}{5} : \frac{16}{25} = \frac{16}{5} * \frac{25}{16} = 5$
Пожауйста, оцените решение