$a)4,67-\left(3\frac{5}{6}-\frac{1}{3}\right)=4,67-\left(3\frac{5}{6}-\frac{2}{6}\right)=4,67-3\frac{3}{6}=4,67-3\frac{1}{2}=4,67-3,5=1,17$  

$b)2,8+1\frac{1}{3}\cdot 0,9=2,8+\frac{4}{3}\cdot \frac{9}{10}=2,8+\frac{4}{1}\cdot \frac{3}{10}=2,8+\frac{12}{10}=2,8+1,2=4$  

$c)3,6:\frac{3}{5}-1\frac{1}{5}=\frac{36}{10}\cdot \frac{5}{3}-1\frac{1}{5}=$   $\frac{12}{10}\cdot \frac{5}{1}-1\frac{1}{5}=$   $\frac{12}{2}\cdot \frac{1}{1}-1\frac{1}{5}=$   $6-1\frac{1}{5}=4\frac{4}{5}$  

$d){0,2}^2\cdot \left(1,6-\frac{2}{5}\right)=0,04\cdot \left(1,6-\frac{4}{10}\right)=0,04\cdot \left(1,6-0,4\right)=0,04\cdot 1,2=0,048$  

$e)2,8\cdot 1\frac{1}{4}-\frac{2}{3}\cdot 0,75=\frac{28}{10}\cdot \frac{5}{4}-\frac{2}{3}\cdot \frac{3}{4}=$   $\frac{7}{10}\cdot \frac{5}{1}-\frac{2}{1}\cdot \frac{1}{4}=$   $\frac{7}{2}\cdot \frac{1}{1}-\frac{1}{1}\cdot \frac{1}{2}=$   $\frac{7}{2}-\frac{1}{2}=\frac{6}{2}=3$  

$f)\left(4,5-1,1\right)\cdot 2\cdot \frac{3}{4}-1=\left(4,5-1,1\right)\cdot \frac{6}{4}-1=3,4\cdot \frac{3}{2}-1=\frac{34}{10}\cdot \frac{3}{2}-1=$   $\frac{17}{10}\cdot \frac{3}{1}-1=\frac{51}{10}-1=5,1-1=4,1$