Subtract 15/20 from 5/7
5/7 - 15/20 is -1/28.
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,
5/7 = 5 × 20/7 × 20 = 100/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
15/20 = 15 × 7/20 × 7 = 105/140 - Subtract the two like fractions:
100/140 - 105/140 = 100 - 105/140 = -5/140 - After reducing the fraction, the answer is -1/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/7-15/20 5/7-30/20 5/14-15/20 5/7-15/40 15/7-15/20 5/7-45/20 5/21-15/20 5/7-15/60 25/7-15/20 5/7-75/20 5/35-15/20 35/7-15/20 5/49-15/20