Реши примеры с дробями: 1) 4/25 + 15/4

1) $\frac{4}{25} + \frac{15}{4} = \frac{16}{100} + \frac{375}{100} = \frac{391}{100} = 3\frac{91}{100}$ 2) $\frac{9}{4} + \frac{8}{5} = \frac{45}{20} + \frac{32}{20} = \frac{77}{20} = 3\frac{17}{20}$ 3) $\frac{3}{2} - \frac{9}{5} = \frac{15}{10} - \frac{18}{10} = -\frac{3}{10}$ 4) $\frac{3}{4} - \frac{9}{25} = \frac{75}{100} - \frac{36}{100} = \frac{39}{100}$ 5) $\frac{6}{5} * \frac{3}{4} = \frac{18}{20} = \frac{9}{10}$ 6) $\frac{5}{3} * \frac{9}{2} = \frac{45}{6} = \frac{15}{2} = 7\frac{1}{2}$ 7) $\frac{12}{5} : \frac{15}{2} = \frac{12}{5} * \frac{2}{15} = \frac{24}{75} = \frac{8}{25}$ 8) $\frac{21}{2} : \frac{3}{5} = \frac{21}{2} * \frac{5}{3} = \frac{105}{6} = \frac{35}{2} = 17\frac{1}{2}$ 9) $\frac{1}{\frac{1}{36} + \frac{1}{45}} = \frac{1}{\frac{5}{180} + \frac{4}{180}} = \frac{1}{\frac{9}{180}} = \frac{1}{\frac{1}{20}} = 20$ **Ответы:** 1) $3\frac{91}{100}$ 2) $3\frac{17}{20}$ 3) $-\frac{3}{10}$ 4) $\frac{39}{100}$ 5) $\frac{9}{10}$ 6) $7\frac{1}{2}$ 7) $\frac{8}{25}$ 8) $17\frac{1}{2}$ 9) $20$