[tex]a] \ -2\frac{1}{3}+(-3\frac{4}{5})=-(2\frac{5}{15}+3\frac{12}{15})=-5\frac{17}{15}=-6\frac{2}{15}\\\\b] \ 1\frac{2}{3}-(-2\frac{5}{6})=1\frac{2}{3}+2\frac{5}{6}=1\frac{4}{6}+2\frac{5}{6}=3\frac{9}{6}=3\frac{3}{2}=4\frac{1}{2}\\\\c] \ 1\frac{1}{2}\cdot(-2\frac{3}{5})=\frac{3}{2}\cdot(-\frac{13}{5})=-\frac{26}{10}=-2\frac{6}{10}=-2\frac{3}{5}\\\\d] \ 3\frac{3}{4}:2\frac{1}{2}=\frac{15}{4}:\frac{5}{2}=\frac{15}{4}\cdot\frac{2}{5}=\frac{3}{2}=1\frac{1}{2}[/tex]
