Subtract 5/21 from 8/20
8/20 - 5/21 is 17/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
8/20 = 8 × 21/20 × 21 = 168/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
5/21 = 5 × 20/21 × 20 = 100/420 - Subtract the two like fractions:
168/420 - 100/420 = 168 - 100/420 = 68/420 - After reducing the fraction, the answer is 17/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/20-5/21 8/20-10/21 8/40-5/21 8/20-5/42 24/20-5/21 8/20-15/21 8/60-5/21 8/20-5/63 40/20-5/21 8/20-25/21 56/20-5/21 8/20-35/21