Math Problem Solver

\[ \frac{-1}{4} + \frac{3}{5} - \frac{1}{2} + \frac{7}{10} = \frac{11}{20} = 0.55 \]

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of \(\frac{-1}{4}\), \(\frac{3}{5}\), \(\frac{-1}{2}\), and \(\frac{7}{10}\) is \(20\). \[ \begin{aligned} \frac{-1}{4} + \frac{3}{5} - \frac{1}{2} + \frac{7}{10} &= \frac{-1 \cdot 5}{4 \cdot 5} + \frac{3 \cdot 4}{5 \cdot 4} + \frac{-1 \cdot 10}{2 \cdot 10} + \frac{7 \cdot 2}{10 \cdot 2} \\ &= \frac{-5 + 12 + -10 + 14}{20} \\ &= \frac{11}{20} \end{aligned} \]