Subtract 5/15 from 28/21
1st number: 1 7/21, 2nd number: 5/15
28/21 - 5/15 is 1/1.
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,
5/15 = 5 × 7/15 × 7 = 35/105 - Subtract the two like fractions:
140/105 - 35/105 = 140 - 35/105 = 105/105 - After reducing the fraction, the answer is 1/1
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21-5/15 28/21-10/15 28/42-5/15 28/21-5/30 84/21-5/15 28/63-5/15 28/21-5/45 28/21-25/15 28/21-5/75 28/21-35/15