## Prealgebra (7th Edition)

$\frac{3}{10}$
The least common denominator is 10. Convert to like fractions and subtract. $\frac{7}{10}-\frac{2}{5}$ =$\frac{7}{10}-\frac{2\times2}{5\times2}$ =$\frac{7}{10}-\frac{4}{10}$ =$\frac{3}{10}$