Subtract 28/81 from 4/21
4/21 - 28/81 is -88/567.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 81 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 21 × 27 = 567,
4/21 = 4 × 27/21 × 27 = 108/567 - Likewise, for the 2nd fraction, since 81 × 7 = 567,
28/81 = 28 × 7/81 × 7 = 196/567 - Subtract the two like fractions:
108/567 - 196/567 = 108 - 196/567 = -88/567
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/21-28/81 4/21-56/81 4/42-28/81 12/21-28/81 4/21-84/81 4/63-28/81 20/21-28/81 28/21-28/81