Answer
$-\frac{11}{30}$
Work Step by Step
LCD is 30.
$-\frac{2}{5}+\frac{1}{3}-\frac{3}{10}=-\frac{2\times6}{5\times6}+\frac{1\times10}{3\times10}-\frac{3\times3}{10\times3}=-\frac{12}{30}+\frac{10}{30}-\frac{9}{30}=\frac{-12+10-9}{30}=\frac{-11}{30}$