Subtract 21/7 from 2/8
1st number: 2/8, 2nd number: 3 0/7
2/8 - 21/7 is -11/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 7 is 56
Next, find the equivalent fraction of both fractional numbers with denominator 56 - For the 1st fraction, since 8 × 7 = 56,
2/8 = 2 × 7/8 × 7 = 14/56 - Likewise, for the 2nd fraction, since 7 × 8 = 56,
21/7 = 21 × 8/7 × 8 = 168/56 - Subtract the two like fractions:
14/56 - 168/56 = 14 - 168/56 = -154/56 - After reducing the fraction, the answer is -11/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/8-21/7 2/8-42/7 2/16-21/7 2/8-21/14 6/8-21/7 2/8-63/7 2/24-21/7 10/8-21/7 2/40-21/7 2/8-21/35 14/8-21/7 2/56-21/7 2/8-21/49