Краткий ответ:
\(\displaystyle \frac{59}{6}=9\frac{5}{6}\)
\(\displaystyle \frac{58}{25}=2{,}32\)
1) \(\left(8\frac{7}{12}-2\frac{17}{36}\right)\cdot2{,}7-4\frac13:0{,}65\)
Переведём смешанные и десятичные дроби:
\[ 8\frac{7}{12}=\frac{103}{12}=\frac{309}{36},\qquad 2\frac{17}{36}=\frac{89}{36} \]
\[ \frac{309}{36}-\frac{89}{36} =\frac{220}{36} =\frac{55}{9} \]
\[ 2{,}7=\frac{27}{10},\qquad 4\frac13=\frac{13}{3},\qquad 0{,}65=\frac{13}{20} \]
Подставим:
\[ \frac{55}{9}\cdot\frac{27}{10} -\frac{13}{3}:\frac{13}{20} \]
\[ =\frac{33}{2}-\frac{20}{3} =\frac{99-40}{6} =\frac{59}{6} =9\frac56 \]
2) \(\left(1\frac{11}{24}+\frac{13}{36}\right)\cdot1{,}44-\frac{8}{15}\cdot0{,}5625\)
Приведём дроби к знаменателю \(72\):
\[ 1\frac{11}{24}+\frac{13}{36} =1+\frac{33}{72}+\frac{26}{72} =1+\frac{59}{72} =\frac{131}{72} \]
\[ 1{,}44=\frac{36}{25},\qquad 0{,}5625=\frac{9}{16} \]
\[ \frac{131}{72}\cdot\frac{36}{25} -\frac{8}{15}\cdot\frac{9}{16} \]
\[ =\frac{131}{50}-\frac{3}{10} =\frac{131}{50}-\frac{15}{50} =\frac{116}{50} =\frac{58}{25} =2{,}32 \]
Проверка: во втором выражении \(2{,}62-0{,}3=2{,}32\), результат совпадает.
