Subtract 16/20 from 1/21
1/21 - 16/20 is -79/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
1/21 = 1 × 20/21 × 20 = 20/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
16/20 = 16 × 21/20 × 21 = 336/420 - Subtract the two like fractions:
20/420 - 336/420 = 20 - 336/420 = -316/420 - After reducing the fraction, the answer is -79/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/21-16/20 1/21-32/20 1/42-16/20 1/21-16/40 3/21-16/20 1/21-48/20 1/63-16/20 1/21-16/60 5/21-16/20 1/21-80/20 7/21-16/20