Subtract 2/7 from 15/21
15/21 - 2/7 is 3/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
15/21 = 15 × 1/21 × 1 = 15/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
2/7 = 2 × 3/7 × 3 = 6/21 - Subtract the two like fractions:
15/21 - 6/21 = 15 - 6/21 = 9/21 - After reducing the fraction, the answer is 3/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21-2/7 15/21-4/7 15/42-2/7 15/21-2/14 45/21-2/7 15/21-6/7 15/63-2/7 15/21-2/21 75/21-2/7 15/21-10/7 15/21-2/35 15/21-14/7 15/21-2/49