КОНТРОЛЬНАЯ РАБОТА № 11. ВАРИАНТ 1 1. Выполните действие: 35 a)7 11' -6 5 6)25 18' 1 B)3-19; 33 r) 1.14; 7 5 10 д): 27 12: 6. 13 e):

Решение:

a) \[\frac{3}{7} - \frac{5}{11} = \frac{3 \cdot 11}{7 \cdot 11} - \frac{5 \cdot 7}{11 \cdot 7} = \frac{33}{77} - \frac{35}{77} = \frac{33 - 35}{77} = -\frac{2}{77}\]

б) \[\frac{6}{25} - \frac{5}{18} = \frac{6 \cdot 18}{25 \cdot 18} - \frac{5 \cdot 25}{18 \cdot 25} = \frac{108}{450} - \frac{125}{450} = \frac{108 - 125}{450} = -\frac{17}{450}\]

в) \(3 \frac{1}{5} - 1 \frac{1}{9} = \frac{16}{5} - \frac{10}{9} = \frac{16 \cdot 9}{5 \cdot 9} - \frac{10 \cdot 5}{9 \cdot 5} = \frac{144}{45} - \frac{50}{45} = \frac{144 - 50}{45} = \frac{94}{45} = 2 \frac{4}{45}\)

г) \(1 \frac{3}{7} = \frac{10}{7}\) ; \(1 \frac{3}{7} \cdot 14 = \frac{10}{7} \cdot 14 = \frac{10 \cdot 14}{7} = \frac{140}{7} = 20\)

д) \(\frac{5}{9} - \frac{10}{27} = \frac{5 \cdot 3}{9 \cdot 3} - \frac{10}{27} = \frac{15}{27} - \frac{10}{27} = \frac{15 - 10}{27} = \frac{5}{27}\)

e) \(\frac{12}{13} \cdot 6 = \frac{12 \cdot 6}{13} = \frac{72}{13} = 5 \frac{7}{13}\)