510 выполни страница 174

Решите задачу:

$( \frac{7}{15} - \frac{1}{6} )+ \frac{2}{5} =( \frac{14}{30} - \frac{5}{30} )+ \frac{2}{5} = \frac{9}{30} + \frac{2}{5} = \frac{3}{10} + \frac{4}{10} = \frac{7}{10} =0,7$

$( \frac{3}{8} - \frac{1}{9} )+ \frac{25}{36} =( \frac{27}{72} - \frac{8}{72} )+ \frac{25}{36} = \frac{19}{72} + \frac{50}{72} =\frac{69}{72} =\frac{23}{24}$

$( \frac{8}{9} - \frac{5}{6} )+ \frac{2}{3} =( \frac{16}{18} - \frac{15}{18} )+ \frac{2}{3} = \frac{1}{18} + \frac{12}{18} =\frac{13}{18}$

$( \frac{7}{8} - \frac{13}{20} )+ \frac{9}{10} =( \frac{35}{40} - \frac{26}{40} )+ \frac{9}{10} =\frac{9}{40} + \frac{36}{40} =\frac{45}{40} =\frac{9}{8} =1 \frac{1}{8} =1,125$

$( \frac{7}{18} - \frac{1}{12} )+ \frac{5}{6} =( \frac{14}{36} - \frac{3}{36} )+ \frac{5}{6} = \frac{11}{36} + \frac{30}{36} = \frac{41}{36} =1 \frac{5}{36}$

$( \frac{3}{4} - \frac{8}{15} )+ \frac{17}{20} =( \frac{45}{60} - \frac{32}{60} )+ \frac{17}{20} = \frac{13}{60} + \frac{51}{60} = \frac{64}{60} = \frac{16}{15} = 1\frac{1}{15}$