Math Problem Solver

$$\frac{3}{20} - \frac{1}{4} = - \frac{1}{10} = -0.1$$

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