Subtract 15/81 from 7/28
7/28 - 15/81 is 7/108.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 81 is 2268
Next, find the equivalent fraction of both fractional numbers with denominator 2268 - For the 1st fraction, since 28 × 81 = 2268,
7/28 = 7 × 81/28 × 81 = 567/2268 - Likewise, for the 2nd fraction, since 81 × 28 = 2268,
15/81 = 15 × 28/81 × 28 = 420/2268 - Subtract the two like fractions:
567/2268 - 420/2268 = 567 - 420/2268 = 147/2268 - After reducing the fraction, the answer is 7/108
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/28-15/81 7/28-30/81 7/56-15/81 21/28-15/81 7/28-45/81 7/84-15/81 35/28-15/81 7/28-75/81 49/28-15/81