Subtract 21/10 from 1/81
1st number: 1/81, 2nd number: 2 1/10
1/81 - 21/10 is -1691/810.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 10 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 81 × 10 = 810,
1/81 = 1 × 10/81 × 10 = 10/810 - Likewise, for the 2nd fraction, since 10 × 81 = 810,
21/10 = 21 × 81/10 × 81 = 1701/810 - Subtract the two like fractions:
10/810 - 1701/810 = 10 - 1701/810 = -1691/810
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/81-21/10 1/81-42/10 1/81-21/20 3/81-21/10 1/81-63/10 1/81-21/30 5/81-21/10 1/81-21/50 7/81-21/10 1/81-21/70