Subtract 3/7 from 81/20
1st number: 4 1/20, 2nd number: 3/7
81/20 - 3/7 is 507/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 7 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
81/20 = 81 × 7/20 × 7 = 567/140 - Likewise, for the 2nd fraction, since 7 × 20 = 140,
3/7 = 3 × 20/7 × 20 = 60/140 - Subtract the two like fractions:
567/140 - 60/140 = 567 - 60/140 = 507/140 - In mixed form: 387/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/20-6/7 81/40-3/7 81/20-3/14 81/20-9/7 81/60-3/7 81/20-3/21 81/20-15/7 81/20-3/35 81/20-21/7 81/20-3/49