Subtract 28/56 from 15/42
15/42 - 28/56 is -1/7.
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,
15/42 = 15 × 4/42 × 4 = 60/168 - Likewise, for the 2nd fraction, since 56 × 3 = 168,
28/56 = 28 × 3/56 × 3 = 84/168 - Subtract the two like fractions:
60/168 - 84/168 = 60 - 84/168 = -24/168 - After reducing the fraction, the answer is -1/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/42-28/56 15/84-28/56 45/42-28/56 15/42-84/56 75/42-28/56