Subtract 20/21 from 30/28
1st number: 1 2/28, 2nd number: 20/21
30/28 - 20/21 is 5/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 28 × 3 = 84,
30/28 = 30 × 3/28 × 3 = 90/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
20/21 = 20 × 4/21 × 4 = 80/84 - Subtract the two like fractions:
90/84 - 80/84 = 90 - 80/84 = 10/84 - After reducing the fraction, the answer is 5/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/28-20/21 30/28-40/21 30/56-20/21 30/28-20/42 90/28-20/21 30/28-60/21 30/84-20/21 30/28-20/63