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

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

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

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

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

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

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

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