Subtract 1/15 from 28/21
1st number: 1 7/21, 2nd number: 1/15
28/21 - 1/15 is 19/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
28/21 = 28 × 5/21 × 5 = 140/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
1/15 = 1 × 7/15 × 7 = 7/105 - Subtract the two like fractions:
140/105 - 7/105 = 140 - 7/105 = 133/105 - After reducing the fraction, the answer is 19/15
- In mixed form: 14/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21-1/15 28/21-2/15 28/42-1/15 28/21-1/30 84/21-1/15 28/21-3/15 28/63-1/15 28/21-1/45 28/21-5/15 28/21-1/75 28/21-7/15