Subtract 28/20 from 21/12
1st number: 1 9/12, 2nd number: 1 8/20
21/12 - 28/20 is 7/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 20 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 12 × 5 = 60,
21/12 = 21 × 5/12 × 5 = 105/60 - Likewise, for the 2nd fraction, since 20 × 3 = 60,
28/20 = 28 × 3/20 × 3 = 84/60 - Subtract the two like fractions:
105/60 - 84/60 = 105 - 84/60 = 21/60 - After reducing the fraction, the answer is 7/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/12-28/20 21/12-56/20 21/24-28/20 21/12-28/40 63/12-28/20 21/12-84/20 21/36-28/20 21/12-28/60 21/60-28/20 21/84-28/20