Subtract 28/35 from 7/21
7/21 - 28/35 is -7/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 35 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
7/21 = 7 × 5/21 × 5 = 35/105 - Likewise, for the 2nd fraction, since 35 × 3 = 105,
28/35 = 28 × 3/35 × 3 = 84/105 - Subtract the two like fractions:
35/105 - 84/105 = 35 - 84/105 = -49/105 - After reducing the fraction, the answer is -7/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-28/35 7/21-56/35 7/42-28/35 7/21-28/70 7/21-84/35 7/63-28/35 35/21-28/35 49/21-28/35