Subtract 8/28 from 1/21
1/21 - 8/28 is -5/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
1/21 = 1 × 4/21 × 4 = 4/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
8/28 = 8 × 3/28 × 3 = 24/84 - Subtract the two like fractions:
4/84 - 24/84 = 4 - 24/84 = -20/84 - After reducing the fraction, the answer is -5/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/21-8/28 1/21-16/28 1/42-8/28 1/21-8/56 3/21-8/28 1/21-24/28 1/63-8/28 1/21-8/84 5/21-8/28 1/21-40/28 7/21-8/28 1/21-56/28