Subtract 9/28 from 21/12
1st number: 1 9/12, 2nd number: 9/28
21/12 - 9/28 is 10/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
21/12 = 21 × 7/12 × 7 = 147/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
9/28 = 9 × 3/28 × 3 = 27/84 - Subtract the two like fractions:
147/84 - 27/84 = 147 - 27/84 = 120/84 - After reducing the fraction, the answer is 10/7
- In mixed form: 13/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/12-9/28 21/12-18/28 21/24-9/28 21/12-9/56 63/12-9/28 21/12-27/28 21/36-9/28 21/12-9/84 21/12-45/28 21/60-9/28 21/12-63/28 21/84-9/28