Subtract 3/20 from 16/21
16/21 - 3/20 is 257/420.
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,
16/21 = 16 × 20/21 × 20 = 320/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
3/20 = 3 × 21/20 × 21 = 63/420 - Subtract the two like fractions:
320/420 - 63/420 = 320 - 63/420 = 257/420
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 32/21-3/20 16/21-6/20 16/42-3/20 16/21-3/40 48/21-3/20 16/21-9/20 16/63-3/20 16/21-3/60 80/21-3/20 16/21-15/20 16/21-21/20