Subtract 28/16 from 20/21
1st number: 20/21, 2nd number: 1 12/16
20/21 - 28/16 is -67/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 16 is 336
Next, find the equivalent fraction of both fractional numbers with denominator 336 - For the 1st fraction, since 21 × 16 = 336,
20/21 = 20 × 16/21 × 16 = 320/336 - Likewise, for the 2nd fraction, since 16 × 21 = 336,
28/16 = 28 × 21/16 × 21 = 588/336 - Subtract the two like fractions:
320/336 - 588/336 = 320 - 588/336 = -268/336 - After reducing the fraction, the answer is -67/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/21-28/16 20/21-56/16 20/42-28/16 20/21-28/32 60/21-28/16 20/21-84/16 20/63-28/16 20/21-28/48 20/21-28/80