2.53. Найдите значение выражения: а) \(\frac49+\frac79-\frac19\); б) \(5\frac6{39}+4\frac7{78}\); в) \(\frac78\cdot\frac4{35}\cdot\frac{10}{9}\); г) \(7\frac{13}{15}-3\frac{11}{30}\); д) \(\left(\frac12:\frac34-\frac49\right)\cdot\frac53\).

а) \(\frac49+\frac79-\frac19=\frac{4+7-1}{9}=\frac{10}{9}=1\frac19\).

б) \(5\frac6{39}+4\frac7{78}=5\frac4{26}+4\frac7{78}=5\frac{12}{78}+4\frac7{78}=9\frac{19}{78}\).

в) \(\frac78\cdot\frac4{35}\cdot\frac{10}{9}=\frac{1}{2}\cdot\frac{4}{35}\cdot\frac{10}{9}=\frac4{63}\).

г) \(7\frac{13}{15}-3\frac{11}{30}=7\frac{26}{30}-3\frac{11}{30}=4\frac{15}{30}=4\frac12\).

д) \(\left(\frac12:\frac34-\frac49\right)\cdot\frac53=\left(\frac23-\frac49\right)\cdot\frac53=\frac29\cdot\frac53=\frac{10}{27}\).

Ответ: а) \(1\frac19\); б) \(9\frac{19}{78}\); в) \(\frac4{63}\); г) \(4\frac12\); д) \(\frac{10}{27}\).