a) 

$\frac{1}{2}+1,5=0,5+1,5=2$  

b)

$3,2-1\frac{1}{3}=3\frac{2}{10}-1\frac{1}{3}=3\frac{1}{5}-1\frac{1}{3}=3\frac{3}{15}-1\frac{5}{15}=$ $2\frac{18}{15}-1\frac{5}{15}=1\frac{13}{15}$  

c) 

$2,4\cdot \frac{3}{8}=2\frac{4}{10}\cdot \frac{3}{8}=2\frac{2}{5}\cdot \frac{3}{8}=\frac{{\sout{12}}^3}{5}\cdot \frac{3}{{\sout{8}}^2}=\frac{3}{5}\cdot \frac{3}{2}=\frac{9}{10}=0,9$  

d) 

$2\frac{3}{4}:2,75=2,75:2,75=1$