Subtract 5/8 from 7/21
7/21 - 5/8 is -7/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
7/21 = 7 × 8/21 × 8 = 56/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
5/8 = 5 × 21/8 × 21 = 105/168 - Subtract the two like fractions:
56/168 - 105/168 = 56 - 105/168 = -49/168 - After reducing the fraction, the answer is -7/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-5/8 7/21-10/8 7/42-5/8 7/21-5/16 7/21-15/8 7/63-5/8 7/21-5/24 35/21-5/8 7/21-25/8 7/21-5/40 49/21-5/8 7/21-35/8 7/21-5/56