Subtract 81/28 from 2/21
1st number: 2/21, 2nd number: 2 25/28
2/21 - 81/28 is -235/84.
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,
2/21 = 2 × 4/21 × 4 = 8/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
81/28 = 81 × 3/28 × 3 = 243/84 - Subtract the two like fractions:
8/84 - 243/84 = 8 - 243/84 = -235/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/21-81/28 2/42-81/28 2/21-81/56 6/21-81/28 2/63-81/28 2/21-81/84 10/21-81/28 14/21-81/28