Subtract 28/81 from 70/21
1st number: 3 7/21, 2nd number: 28/81
70/21 - 28/81 is 242/81.
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,
70/21 = 70 × 27/21 × 27 = 1890/567 - Likewise, for the 2nd fraction, since 81 × 7 = 567,
28/81 = 28 × 7/81 × 7 = 196/567 - Subtract the two like fractions:
1890/567 - 196/567 = 1890 - 196/567 = 1694/567 - After reducing the fraction, the answer is 242/81
- In mixed form: 280/81
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/21-56/81 70/42-28/81 70/21-84/81 70/63-28/81