Math Problem Solver

\[ \frac{3}{25} - \frac{21}{50} = - \frac{3}{10} = -0.3 \]

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of \(\frac{3}{25}\) and \(\frac{-21}{50}\) is \(50\). \[ \begin{aligned} \frac{3}{25} - \frac{21}{50} &= \frac{3 \cdot 2}{25 \cdot 2} + \frac{-21 \cdot 1}{50 \cdot 1} \\ &= \frac{6 + -21}{50} \\ &= \frac{-15}{50} \\&= - \frac{3}{10} \end{aligned} \]