I. Блок. Найдите значение выражения: а) 1/2 + 33/50; б) 19/2 − 7/25; в) 15/(3·2); г) 1,6/(1 + 1/9); д) 1/(1/30 + 1/42); е) (11/30 − 17/36) : 19/45; ж) (5/6 + 1 1/10) · 24.

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а) \(\frac{1}{2}+\frac{33}{50}=\frac{25}{50}+\frac{33}{50}=\frac{58}{50}=\frac{29}{25}=1\frac{4}{25}\).
б) \(\frac{19}{2}-\frac{7}{25}=\frac{475}{50}-\frac{14}{50}=\frac{461}{50}=9\frac{11}{50}\).
в) \(\frac{15}{3\cdot2}=\frac{15}{6}=\frac{5}{2}=2\frac{1}{2}\).
г) \(\frac{1{,}6}{1+\frac{1}{9}}=\frac{\frac{8}{5}}{\frac{10}{9}}=\frac{8}{5}\cdot\frac{9}{10}=\frac{36}{25}=1{,}44\).
д) \(\frac{1}{\frac{1}{30}+\frac{1}{42}}=\frac{1}{\frac{7}{210}+\frac{5}{210}}=\frac{1}{\frac{12}{210}}=\frac{35}{2}=17\frac{1}{2}\).
е) \(\left(\frac{11}{30}-\frac{17}{36}\right):\frac{19}{45}=\left(\frac{66}{180}-\frac{85}{180}\right)\cdot\frac{45}{19}=-\frac{19}{180}\cdot\frac{45}{19}=-\frac{1}{4}\).
ж) \(\left(\frac{5}{6}+1\frac{1}{10}\right)\cdot24=\left(\frac{25}{30}+\frac{33}{30}\right)\cdot24=\frac{29}{15}\cdot24=\frac{232}{5}=46\frac{2}{5}\).

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