$a)\frac{8:\left(-1\frac{3}{5}\right)-\left(4\frac{1}{2}\cdot 1\frac{2}{3}-3\frac{3}{4}\right)}{\frac{1}{2}\cdot 2\frac{1}{2}}=\frac{8:\left(-\frac{8}{5}\right)-\left(\frac{{\sout{9}}^3}{2}\cdot \frac{5}{{\sout{3}}^1}-3\frac{3}{4}\right)}{\frac{1}{2}\cdot \frac{5}{2}}=\frac{8\cdot \left(-\frac{5}{8}\right)-\left(\frac{15}{2}-3\frac{3}{4}\right)}{\frac{5}{4}}=$

$=\frac{-5-\left(7\frac{1}{2}-3\frac{3}{4}\right)}{\frac{5}{4}}=\left(-5-\left(7\frac{2}{4}-3\frac{3}{4}\right)\right):\frac{5}{4}=\left(-5-\left(6\frac{6}{4}-3\frac{3}{4}\right)\right):\frac{5}{4}=$

$=\left(-5-3\frac{3}{4}\right)\cdot \frac{4}{5}=-8\frac{3}{4}\cdot \frac{4}{5}=-\frac{35}{{\sout{4}}^1}\cdot \frac{{\sout{4}}^1}{5}=-\frac{35}{5}=-7$  

 

 

 

 

$b)\frac{\frac{1}{2}-\frac{2}{5}:\left(1\frac{2}{3}-2\frac{1}{5}\right)}{\frac{2}{3}\cdot 1\frac{1}{2}-\frac{3}{4}}=\frac{\frac{1}{2}-\frac{2}{5}:\left(1\frac{10}{15}-2\frac{3}{15}\right)}{\frac{2}{3}\cdot \frac{3}{2}-\frac{3}{4}}=\frac{\frac{1}{2}-\frac{2}{5}:\left(-\left(2\frac{3}{15}-1\frac{10}{15}\right)\right)}{1-\frac{3}{4}}=$

$=\frac{\frac{1}{2}-\frac{2}{5}:\left(-\left(1\frac{18}{15}-1\frac{10}{15}\right)\right)}{\frac{1}{4}}=\frac{\frac{1}{2}-\frac{2}{5}:\left(-\frac{8}{15}\right)}{\frac{1}{4}}=\frac{\frac{1}{2}-\frac{{\sout{2}}^1}{{\sout{5}}^1}\cdot \left(-\frac{{\sout{15}}^3}{{\sout{8}}^4}\right)}{\frac{1}{4}}=$

$=\frac{\frac{1}{2}+\frac{3}{4}}{\frac{1}{4}}=\left(\frac{1}{2}+\frac{3}{4}\right):\frac{1}{4}=\left(\frac{1}{2}+\frac{3}{4}\right)\cdot \frac{4}{1}=\left(\frac{2}{4}+\frac{3}{4}\right)\cdot \frac{4}{1}=\frac{5}{{\sout{4}}^1}\cdot \frac{{\sout{4}}^1}{1}=5$

 

 

 

$c)\frac{\left(\frac{2}{{\sout{3}}^1}\cdot {\sout{2,7}}^{0,9}-\frac{7}{15}:\frac{1}{3}\right):\frac{1}{25}\cdot \left[\frac{3}{4}-\frac{1}{6}\right]}{\frac{8}{15}+0,3}=\frac{\left(1,8-\frac{7}{{\sout{15}}^5}\cdot \frac{{\sout{3}}^1}{1}\right)\cdot \frac{25}{1}\cdot \left[\frac{9}{12}-\frac{2}{12}\right]}{\frac{8}{15}+\frac{3}{10}}=$

$=\frac{\left(1,8-\frac{7}{5}\right)\cdot 25\cdot \frac{7}{12}}{\frac{16}{30}+\frac{9}{30}}=\frac{\left(1,8-1,4\right)\cdot 25\cdot \frac{7}{12}}{\frac{25}{30}}=\frac{0,4\cdot 25\cdot \frac{7}{12}}{\frac{5}{6}}=$

$=\left(10\cdot \frac{7}{12}\right):\frac{5}{6}=\frac{70}{{\sout{12}}^2}\cdot \frac{{\sout{6}}^1}{5}=\frac{70}{10}=7$

 

 

 

$d)\frac{\left(\frac{1}{5}+1,3\right):\frac{3}{2}-\left(18\frac{3}{4}-4,95\right):2\frac{3}{10}}{1\frac{1}{5}:0,6-2\frac{2}{5}\cdot 1,25}=\frac{\left(0,2+1,3\right)\cdot \frac{2}{3}-\left(18,75-4,95\right):2,3}{1,2:0,6-2\frac{2}{5}\cdot 1\frac{1}{4}}=$

$=\frac{{\sout{1,5}}^{0,5}\cdot \frac{2}{{\sout{3}}^1}-13,8:2,3}{12:6-\frac{{\sout{12}}^3}{{\sout{5}}^1}\cdot \frac{{\sout{5}}^1}{{\sout{4}}^1}}=\frac{1-138:23}{2-3}=\frac{1-6}{-1}=\frac{-5}{-1}=5$