Ответ:
а)
\(9\frac{1}{4}=\frac{37}{4}\), \(3\frac{2}{3}=\frac{11}{3}\), \(4\frac{1}{2}=\frac{9}{2}\), \(10\frac{4}{5}=\frac{54}{5}\), \(4\frac{7}{12}=\frac{55}{12}\).
\(\frac{37}{4}\cdot8-\frac{11}{3}\cdot\frac{9}{2}-\frac{54}{5}\cdot\frac{55}{12}=74-\frac{33}{2}-\frac{99}{2}=74-66=8\).
б)
\(-31,7:63,4=-0,5\), \(23,4:(-11,7)=-2\).
\(-0,5-(-2)\cdot(-2,4)=-0,5-4,8=-5,3\).
в)
\(\frac{10}{27}-\frac{25}{28}=\frac{280-675}{756}=-\frac{395}{756}\).
\(-\frac{11}{14}+\frac{24}{35}=-\frac{55}{70}+\frac{48}{70}=-\frac{1}{10}\).
\(-\frac{395}{756}:\left(-\frac{1}{10}\right)=\frac{3950}{756}=\frac{1975}{378}\).
Ответ: а) 8; б) −5,3; в) \(\frac{1975}{378}\).
