186. Выполните действия: 1) \frac{5}{12} + \frac{3}{12}; 2) \frac{7}{15} - \frac{4}{15}; 3) \frac{8}{23} + \frac{5}{23} - \frac{7}{23}; 4) \frac{34}{41} - \frac{20}{41} + \frac{16}{41}.

1) \(\frac{5}{12} + \frac{3}{12} = \frac{5+3}{12} = \frac{8}{12} = \frac{2}{3}\)

2) \(\frac{7}{15} - \frac{4}{15} = \frac{7-4}{15} = \frac{3}{15} = \frac{1}{5}\)

3) \(\frac{8}{23} + \frac{5}{23} - \frac{7}{23} = \frac{8+5-7}{23} = \frac{6}{23}\)

4) \(\frac{34}{41} - \frac{20}{41} + \frac{16}{41} = \frac{34-20+16}{41} = \frac{30}{41}\)

Ответ: 1) \(\frac{2}{3}\); 2) \(\frac{1}{5}\); 3) \(\frac{6}{23}\); 4) \(\frac{30}{41}\)