Subtract 6/20 from 28/21
1st number: 1 7/21, 2nd number: 6/20
28/21 - 6/20 is 31/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
28/21 = 28 × 20/21 × 20 = 560/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
6/20 = 6 × 21/20 × 21 = 126/420 - Subtract the two like fractions:
560/420 - 126/420 = 560 - 126/420 = 434/420 - After reducing the fraction, the answer is 31/30
- In mixed form: 11/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21-6/20 28/21-12/20 28/42-6/20 28/21-6/40 84/21-6/20 28/21-18/20 28/63-6/20 28/21-6/60 28/21-30/20 28/21-42/20