Subtract 28/20 from 3/7
1st number: 3/7, 2nd number: 1 8/20
3/7 - 28/20 is -34/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 7 × 20 = 140,
3/7 = 3 × 20/7 × 20 = 60/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
28/20 = 28 × 7/20 × 7 = 196/140 - Subtract the two like fractions:
60/140 - 196/140 = 60 - 196/140 = -136/140 - After reducing the fraction, the answer is -34/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/7-28/20 3/7-56/20 3/14-28/20 3/7-28/40 9/7-28/20 3/7-84/20 3/21-28/20 3/7-28/60 15/7-28/20 3/35-28/20 21/7-28/20 3/49-28/20