Math Problem Solver

\[ \frac{7}{10} - \frac{2}{5} = \frac{3}{10} = 0.3 \]

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of \(\frac{7}{10}\) and \(\frac{-2}{5}\) is \(10\). \[ \begin{aligned} \frac{7}{10} - \frac{2}{5} &= \frac{7 \cdot 1}{10 \cdot 1} + \frac{-2 \cdot 2}{5 \cdot 2} \\ &= \frac{7 + -4}{10} \\ &= \frac{3}{10} \end{aligned} \]