Subtract 20/56 from 3/42
3/42 - 20/56 is -2/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 56 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
3/42 = 3 × 4/42 × 4 = 12/168 - Likewise, for the 2nd fraction, since 56 × 3 = 168,
20/56 = 20 × 3/56 × 3 = 60/168 - Subtract the two like fractions:
12/168 - 60/168 = 12 - 60/168 = -48/168 - After reducing the fraction, the answer is -2/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/42-20/56 3/42-40/56 3/84-20/56 9/42-20/56 3/42-60/56 15/42-20/56 21/42-20/56