Subtract 81/21 from 28/3
1st number: 9 1/3, 2nd number: 3 18/21
28/3 - 81/21 is 115/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 3 and 21 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 3 × 7 = 21,
28/3 = 28 × 7/3 × 7 = 196/21 - Likewise, for the 2nd fraction, since 21 × 1 = 21,
81/21 = 81 × 1/21 × 1 = 81/21 - Subtract the two like fractions:
196/21 - 81/21 = 196 - 81/21 = 115/21 - In mixed form: 510/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/3-81/21 28/6-81/21 28/3-81/42 84/3-81/21 28/9-81/21 28/3-81/63 28/15-81/21 28/21-81/21