2/5 − 1/4 = 3/20, which is 0.15 as a decimal.
Answer
\frac{2}{5} - \frac{1}{4} = \textcolor{#0b5c56}{\frac{3}{20}}The difference is 3/20 in simplest form.
\displaystyle 0.153 of 20 equal parts
The problem
\frac{2}{5} - \frac{1}{4}Write both fractions over 20. List multiples of each denominator until they meet:
Multiples of 5: 5, 10, 15, 20
Multiples of 4: 4, 8, 12, 16, 20
The least common denominator is 20. Multiply the top and bottom of each fraction by the same number, so its value doesn't change.
\begin{aligned} \frac{2}{5} &= \frac{2 \times 4}{5 \times 4} = \frac{8}{20} \\[10pt] \frac{1}{4} &= \frac{1 \times 5}{4 \times 5} = \frac{5}{20} \end{aligned}= \textcolor{#0b5c56}{\frac{8}{20}} - \textcolor{#0b5c56}{\frac{5}{20}}Subtract the numerators. Keep the denominator 20.
= \frac{8 - 5}{20} = \textcolor{#0b5c56}{\frac{3}{20}}Check that it can't be simplified. 3 and 20 have no common factor other than 1, so this is the simplest form.
\text{GCF}(3, 20) = 1\begin{aligned} &\frac{2}{5} - \frac{1}{4} \\[8pt] &= \frac{2 \times 4}{5 \times 4} - \frac{1 \times 5}{4 \times 5} && \textcolor{#5b6660}{\textsf{LCD}} \\[8pt] &= \frac{8}{20} - \frac{5}{20} \\[8pt] &= \frac{8 - 5}{20} && \textcolor{#5b6660}{\textsf{subtract}} \\[8pt] &= \textcolor{#0b5c56}{\frac{3}{20}}\end{aligned}| Simplest form | 3/20 |
|---|---|
| Decimal | 0.15 |
| Percent | 15% |
| Same fractions | 1/4 + 2/5, 1/4 × 2/5, 2/5 ÷ 1/4 |
2/5 − 1/4 = 3/20 (0.15 as a decimal).
Write both over a common denominator, subtract the numerators and simplify. The working above shows each step.
Other fractions, mixed numbers or up to five terms: use the Fraction Calculator.