Subtract 4/5 from 8/21
8/21 - 4/5 is -44/105.
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,
8/21 = 8 × 5/21 × 5 = 40/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
4/5 = 4 × 21/5 × 21 = 84/105 - Subtract the two like fractions:
40/105 - 84/105 = 40 - 84/105 = -44/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/21-4/5 8/21-8/5 8/42-4/5 8/21-4/10 24/21-4/5 8/21-12/5 8/63-4/5 8/21-4/15 40/21-4/5 8/21-20/5 8/21-4/25 56/21-4/5 8/21-28/5 8/21-4/35