Subtract 21/8 from 40/7
1st number: 5 5/7, 2nd number: 2 5/8
40/7 - 21/8 is 173/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 8 is 56
Next, find the equivalent fraction of both fractional numbers with denominator 56 - For the 1st fraction, since 7 × 8 = 56,
40/7 = 40 × 8/7 × 8 = 320/56 - Likewise, for the 2nd fraction, since 8 × 7 = 56,
21/8 = 21 × 7/8 × 7 = 147/56 - Subtract the two like fractions:
320/56 - 147/56 = 320 - 147/56 = 173/56 - In mixed form: 35/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/7-21/8 40/7-42/8 40/14-21/8 40/7-21/16 40/7-63/8 40/21-21/8 40/7-21/24 40/35-21/8 40/7-21/40 40/49-21/8 40/7-21/56