1.\frac{3,75+2\frac{1}{2}-\frac{2\frac{3}{4}+1,5}{2\frac{1}{2}-1,875}\cdot2,75-1\frac{1}{2}}}{\frac{10}{11}}

1. Выполним действия:

1) $$2\frac{1}{2}=2,5$$

2) $$1\frac{1}{2}=1,5$$

3) $$2\frac{3}{4}=2,75$$

4) $$3,75+2,5=6,25$$

5) $$2,75+1,5=4,25$$

6) $$2,5-1,875=0,625$$

7) $$\frac{4,25}{0,625}=\frac{4250}{625}=\frac{25\cdot170}{25\cdot25}=\frac{25\cdot5\cdot34}{25\cdot5}=\frac{34}{1}=6,8$$

8) $$6,8\cdot2,75=18,7$$

9) $$18,7-1,5=17,2$$

10) $$6,25-17,2=-10,95$$

11) $$\frac{-10,95}{\frac{10}{11}}=\frac{-10,95}{1}:\frac{10}{11}=\frac{-10,95}{1}\cdot\frac{11}{10}=\frac{-1095}{100}\cdot\frac{11}{10}=\frac{-219\cdot5}{20\cdot5}\cdot\frac{11}{10}=\frac{-219}{20}\cdot\frac{11}{10}=\frac{-2409}{200}=-12,045$$

Ответ: $$-12,045$$