Subtract 21/7 from 3/8
1st number: 3/8, 2nd number: 3 0/7
3/8 - 21/7 is -21/8.
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,
3/8 = 3 × 7/8 × 7 = 21/56 - Likewise, for the 2nd fraction, since 7 × 8 = 56,
21/7 = 21 × 8/7 × 8 = 168/56 - Subtract the two like fractions:
21/56 - 168/56 = 21 - 168/56 = -147/56 - After reducing the fraction, the answer is -21/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/8-21/7 3/8-42/7 3/16-21/7 3/8-21/14 9/8-21/7 3/8-63/7 3/24-21/7 15/8-21/7 3/40-21/7 3/8-21/35 21/8-21/7 3/56-21/7 3/8-21/49