Subtract 3/15 from 7/21
7/21 - 3/15 is 2/15.
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,
7/21 = 7 × 5/21 × 5 = 35/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
3/15 = 3 × 7/15 × 7 = 21/105 - Subtract the two like fractions:
35/105 - 21/105 = 35 - 21/105 = 14/105 - After reducing the fraction, the answer is 2/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-3/15 7/21-6/15 7/42-3/15 7/21-3/30 7/21-9/15 7/63-3/15 7/21-3/45 35/21-3/15 7/21-3/75 49/21-3/15 7/21-21/15