What Is 4/5 − 1/2?

Q: What is 4/5 − 1/2?

4/5 − 1/2 = 3/10 (0.3 as a decimal).

4/5 − 1/2 = 3/10, which is 0.3 as a decimal.

Result

Answer

\frac{4}{5} - \frac{1}{2} = \textcolor{#0b5c56}{\frac{3}{10}}

The difference is 3/10 in simplest form.

Decimal: \displaystyle 0.3
Percent: 30%

3 of 10 equal parts

Step-by-step solution

The problem

\frac{4}{5} - \frac{1}{2}

Write both fractions over 10. List multiples of each denominator until they meet:
Multiples of 5: 5, 10
Multiples of 2: 2, 4, 6, 8, 10
The least common denominator is 10. Multiply the top and bottom of each fraction by the same number, so its value doesn't change.
\begin{aligned} \frac{4}{5} &= \frac{4 \times 2}{5 \times 2} = \frac{8}{10} \\[10pt] \frac{1}{2} &= \frac{1 \times 5}{2 \times 5} = \frac{5}{10} \end{aligned}
= \textcolor{#0b5c56}{\frac{8}{10}} - \textcolor{#0b5c56}{\frac{5}{10}}
Subtract the numerators. Keep the denominator 10.
= \frac{8 - 5}{10} = \textcolor{#0b5c56}{\frac{3}{10}}
Check that it can't be simplified. 3 and 10 have no common factor other than 1, so this is the simplest form.
\text{GCF}(3, 10) = 1

All the working together

\begin{aligned} &\frac{4}{5} - \frac{1}{2} \\[8pt]  &= \frac{4 \times 2}{5 \times 2} - \frac{1 \times 5}{2 \times 5} && \textcolor{#5b6660}{\textsf{LCD}} \\[8pt]  &= \frac{8}{10} - \frac{5}{10} \\[8pt]  &= \frac{8 - 5}{10} && \textcolor{#5b6660}{\textsf{subtract}} \\[8pt]  &= \textcolor{#0b5c56}{\frac{3}{10}}\end{aligned}

The answer in other forms

Simplest form	3/10
Decimal	0.3
Percent	30%
Same fractions	1/2 + 4/5, 1/2 × 4/5, 4/5 ÷ 1/2

4/5 minus other fractions

Sum	Answer
4/5 − 1/2	3/10
4/5 − 1/3	7/15
4/5 − 2/3	2/15
4/5 − 1/4	11/20
4/5 − 3/4	1/20
4/5 − 1/5	3/5
4/5 − 2/5	2/5
4/5 − 3/5	1/5
4/5 − 1/6	19/30
4/5 − 1/8	27/40
4/5 − 3/8	17/40
4/5 − 5/8	7/40