Subtract 28/16 from 20/42
1st number: 20/42, 2nd number: 1 12/16
20/42 - 28/16 is -107/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 16 is 336
Next, find the equivalent fraction of both fractional numbers with denominator 336 - For the 1st fraction, since 42 × 8 = 336,
20/42 = 20 × 8/42 × 8 = 160/336 - Likewise, for the 2nd fraction, since 16 × 21 = 336,
28/16 = 28 × 21/16 × 21 = 588/336 - Subtract the two like fractions:
160/336 - 588/336 = 160 - 588/336 = -428/336 - After reducing the fraction, the answer is -107/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-28/16 20/42-56/16 20/84-28/16 20/42-28/32 60/42-28/16 20/42-84/16 20/42-28/48 20/42-28/80