1.005. 2\frac{3}{4}:1,1+3\frac{1}{7}\frac{(2\frac{5}{6}+4,5)\cdot 0,375}{2,5-0,4\cdot 3\frac{1}{7}}2,75-1\frac{1}{2}

1.005.

Решение:

$$\begin{aligned} &\frac{2\frac{3}{4}:1,1+3\frac{1}{7}}{2,5-0,4\cdot 3\frac{1}{7}} = \frac{\frac{11}{4}:\frac{11}{10}+\frac{22}{7}}{2,5-\frac{4}{10} \cdot \frac{22}{7}} = \frac{\frac{11}{4} \cdot \frac{10}{11} + \frac{22}{7}}{2,5 - \frac{88}{70}} = \frac{\frac{10}{4} + \frac{22}{7}}{2,5-\frac{44}{35}} = \frac{\frac{70+88}{28}}{\frac{2,5 \cdot 35 - 44}{35}} = \frac{\frac{158}{28}}{\frac{87,5 - 44}{35}} = \frac{\frac{79}{14}}{\frac{43,5}{35}} = \frac{79}{14} \cdot \frac{35}{43,5} = \frac{79 \cdot 5}{2 \cdot 43,5} = \frac{395}{87} \approx 4,54 \end{aligned}$$ $$\begin{aligned} &\frac{(2\frac{5}{6}+4,5)\cdot 0,375}{2,75-1\frac{1}{2}} = \frac{(\frac{17}{6} + \frac{9}{2}) \cdot \frac{375}{1000}}{\frac{11}{4} - \frac{3}{2}} = \frac{(\frac{17+27}{6}) \cdot \frac{3}{8}}{\frac{11-6}{4}} = \frac{\frac{44}{6} \cdot \frac{3}{8}}{\frac{5}{4}} = \frac{\frac{22}{3} \cdot \frac{3}{8}}{\frac{5}{4}} = \frac{\frac{22}{8}}{\frac{5}{4}} = \frac{11}{4} \cdot \frac{4}{5} = \frac{11}{5} = 2,2 \end{aligned}$$

Ответ: \(\frac{2\frac{3}{4}:1,1+3\frac{1}{7}}{2,5-0,4\cdot 3\frac{1}{7}} \approx 4,54\), \(\frac{(2\frac{5}{6}+4,5)\cdot 0,375}{2,75-1\frac{1}{2}} = 2,2\)