Subtract 5/81 from 21/56
21/56 - 5/81 is 203/648.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 81 is 4536
Next, find the equivalent fraction of both fractional numbers with denominator 4536 - For the 1st fraction, since 56 × 81 = 4536,
21/56 = 21 × 81/56 × 81 = 1701/4536 - Likewise, for the 2nd fraction, since 81 × 56 = 4536,
5/81 = 5 × 56/81 × 56 = 280/4536 - Subtract the two like fractions:
1701/4536 - 280/4536 = 1701 - 280/4536 = 1421/4536 - After reducing the fraction, the answer is 203/648
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/56-5/81 21/56-10/81 63/56-5/81 21/56-15/81 21/56-25/81 21/56-35/81