Subtract 3/7 from 21/15
1st number: 1 6/15, 2nd number: 3/7
21/15 - 3/7 is 34/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 7 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
21/15 = 21 × 7/15 × 7 = 147/105 - Likewise, for the 2nd fraction, since 7 × 15 = 105,
3/7 = 3 × 15/7 × 15 = 45/105 - Subtract the two like fractions:
147/105 - 45/105 = 147 - 45/105 = 102/105 - After reducing the fraction, the answer is 34/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15-3/7 21/15-6/7 21/30-3/7 21/15-3/14 63/15-3/7 21/15-9/7 21/45-3/7 21/15-3/21 21/15-15/7 21/75-3/7 21/15-3/35 21/15-21/7 21/15-3/49