Subtract 7/15 from 6/21
6/21 - 7/15 is -19/105.
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,
6/21 = 6 × 5/21 × 5 = 30/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
7/15 = 7 × 7/15 × 7 = 49/105 - Subtract the two like fractions:
30/105 - 49/105 = 30 - 49/105 = -19/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 12/21-7/15 6/21-14/15 6/42-7/15 6/21-7/30 18/21-7/15 6/21-21/15 6/63-7/15 6/21-7/45 30/21-7/15 6/21-35/15 6/21-7/75 42/21-7/15 6/21-49/15