Math Problem Solver

$$\frac{1}{4} + \frac{1}{5} = \frac{9}{20} = 0.45$$

The sum can be computed by rewriting each term over a common denominator, where the least common denominator of $\frac{1}{4}$ and $\frac{1}{5}$ is $20$. $$\begin{aligned} \frac{1}{4} + \frac{1}{5} &= \frac{1 \cdot 5}{4 \cdot 5} + \frac{1 \cdot 4}{5 \cdot 4} \\ &= \frac{5 + 4}{20} \\ &= \frac{9}{20} \end{aligned}$$