Subtract 20/42 from 15/56
15/56 - 20/42 is -5/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 42 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 56 × 3 = 168,
15/56 = 15 × 3/56 × 3 = 45/168 - Likewise, for the 2nd fraction, since 42 × 4 = 168,
20/42 = 20 × 4/42 × 4 = 80/168 - Subtract the two like fractions:
45/168 - 80/168 = 45 - 80/168 = -35/168 - After reducing the fraction, the answer is -5/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/56-20/42 15/56-40/42 15/56-20/84 45/56-20/42 15/56-60/42 75/56-20/42