\[\boxed{\mathbf{4.}\mathbf{169}}\]
\[\frac{\left( 8,62 - 8,37 + 1\frac{23}{60} + \frac{1}{5} \right) \cdot \frac{3}{11}}{\left( 3,5 - 2\frac{3}{4} \right)\ :\frac{1}{5} - 2,5} =\]
\[= \frac{0,5}{1,25} = \frac{50}{125} = \frac{2}{5} = 0,4\]
\[1)\ 8,62 - 8,37 = 0,25 = \frac{1}{4}\]
\[2)\ 1\frac{23}{60} + \frac{12}{60} = 1\frac{35}{60} = 1\frac{7}{12}\]
\[3)\frac{1}{4} + 1\frac{7}{12} = \frac{3}{12} + 1\frac{7}{12} =\]
\[= 1\frac{10}{12} = 1\frac{5}{6} = \frac{11}{6}\]
\[4)\frac{11}{6} \cdot \frac{3}{11} = \frac{1}{2} = 0,5\]
\[5)\ 3,5 - 2\frac{3}{4} = 3\frac{1}{2} - 2\frac{3}{4} =\]
\[= 3\frac{2}{4} - 2\frac{3}{4} = 2\frac{6}{4} - 2\frac{3}{4} = \frac{3}{4}\]
\[6)\frac{3}{4}\ :\frac{1}{5} = \frac{3}{4} \cdot 5 = \frac{15}{4} = 3,75\]
\[7)\ 3,75 - 2,5 = 1,25\]
Глава 30. Сложение отрицательных чисел