#### Answer

-2

#### Work Step by Step

$\frac{\frac{2}{5}-\frac{1}{2}}{\frac{3}{4}-\frac{7}{10}}$
$=(\frac{2}{5}-\frac{1}{2})\div({\frac{3}{4}-\frac{7}{10}})$
$=(\frac{2\times2}{5\times2}-\frac{1\times5}{2\times5})\div({\frac{3\times5}{4\times5}-\frac{7\times2}{10\times2}})$
$=(\frac{4}{10}-\frac{5}{10})\div({\frac{15}{20}-\frac{14}{20}})$
$=(\frac{-1}{10})\div({\frac{1}{20}})$
$=(\frac{-1}{10})\times({\frac{20}{1}})$
$=\frac{-20}{10}$
$=\frac{-20\div10}{10\div10}$
$=\frac{-2}{1}$
$=-2$