Subtract 3/28 from 20/42
20/42 - 3/28 is 31/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
20/42 = 20 × 2/42 × 2 = 40/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
3/28 = 3 × 3/28 × 3 = 9/84 - Subtract the two like fractions:
40/84 - 9/84 = 40 - 9/84 = 31/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-3/28 20/42-6/28 20/84-3/28 20/42-3/56 60/42-3/28 20/42-9/28 20/42-3/84 20/42-15/28 20/42-21/28