Question

Вычислите: 5/11+1/11, 3/7+1/4, 3/5+2/15, 3/25+2/15, 3/5-2/5, 7/12-3/4, 5/8-5/9, 5/21-3/28

Answer 1

6/11, 19/28, 11/15, 19/75, 1/5, -1/6, 5/72, 11/84

Answer 2

$\frac{5}{11} + \frac{1}{11} = \frac{6}{11}$

$\frac{3}{7} + \frac{1}{4} = \frac{12}{28} + \frac{7}{28} = \frac{19}{28}$

$\frac{3}{5} + \frac{2}{15} = \frac{9}{15} + \frac{2}{15} = \frac{11}{15}$

$\frac{3}{25} + \frac{2}{15} = \frac{9}{75} + \frac{10}{75} = \frac{19}{75}$

$\frac{3}{5} - \frac{2}{5} = \frac{1}{5}$

$\frac{7}{12} - \frac{3}{4} = \frac{7}{12} - \frac{9}{12} = - ( \frac{9}{12} - \frac{7}{12} ) = - \frac{2}{12} = \frac{1}{6}$

$\frac{5}{8} - \frac{5}{9} = \frac{45}{72} - \frac{40}{72} = \frac{5}{72}$
$\frac{5}{21} - \frac{3}{28} = \frac{20}{84} - \frac{9}{84} = \frac{11}{84}$