Subtract 7/5 from 28/21
1st number: 1 7/21, 2nd number: 1 2/5
28/21 - 7/5 is -1/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
28/21 = 28 × 5/21 × 5 = 140/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
7/5 = 7 × 21/5 × 21 = 147/105 - Subtract the two like fractions:
140/105 - 147/105 = 140 - 147/105 = -7/105 - After reducing the fraction, the answer is -1/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21-7/5 28/21-14/5 28/42-7/5 28/21-7/10 84/21-7/5 28/21-21/5 28/63-7/5 28/21-7/15 28/21-35/5 28/21-7/25 28/21-49/5 28/21-7/35