Subtract 10/21 from 2/5
2/5 - 10/21 is -8/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 5 × 21 = 105,
2/5 = 2 × 21/5 × 21 = 42/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
10/21 = 10 × 5/21 × 5 = 50/105 - Subtract the two like fractions:
42/105 - 50/105 = 42 - 50/105 = -8/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/5-10/21 2/5-20/21 2/10-10/21 2/5-10/42 6/5-10/21 2/5-30/21 2/15-10/21 2/5-10/63 10/5-10/21 2/5-50/21 2/25-10/21 14/5-10/21 2/5-70/21 2/35-10/21