Subtract 3/15 from 10/21
10/21 - 3/15 is 29/105.
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,
10/21 = 10 × 5/21 × 5 = 50/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
3/15 = 3 × 7/15 × 7 = 21/105 - Subtract the two like fractions:
50/105 - 21/105 = 50 - 21/105 = 29/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/21-3/15 10/21-6/15 10/42-3/15 10/21-3/30 30/21-3/15 10/21-9/15 10/63-3/15 10/21-3/45 50/21-3/15 10/21-3/75 70/21-3/15 10/21-21/15