Math Problem Solver

\[ \frac{-1}{2} + \frac{3}{5} - \frac{1}{2} + \frac{7}{10} = \frac{3}{10} = 0.3 \]

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of \(\frac{-1}{2}\), \(\frac{3}{5}\), \(\frac{-1}{2}\), and \(\frac{7}{10}\) is \(10\). \[ \begin{aligned} \frac{-1}{2} + \frac{3}{5} - \frac{1}{2} + \frac{7}{10} &= \frac{-1 \cdot 5}{2 \cdot 5} + \frac{3 \cdot 2}{5 \cdot 2} + \frac{-1 \cdot 5}{2 \cdot 5} + \frac{7 \cdot 1}{10 \cdot 1} \\ &= \frac{-5 + 6 + -5 + 7}{10} \\ &= \frac{3}{10} \end{aligned} \]