Subtract 21/4 from 10/81
1st number: 10/81, 2nd number: 5 1/4
10/81 - 21/4 is -1661/324.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 4 is 324
Next, find the equivalent fraction of both fractional numbers with denominator 324 - For the 1st fraction, since 81 × 4 = 324,
10/81 = 10 × 4/81 × 4 = 40/324 - Likewise, for the 2nd fraction, since 4 × 81 = 324,
21/4 = 21 × 81/4 × 81 = 1701/324 - Subtract the two like fractions:
40/324 - 1701/324 = 40 - 1701/324 = -1661/324
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/81-21/4 10/81-42/4 10/81-21/8 30/81-21/4 10/81-63/4 10/81-21/12 50/81-21/4 10/81-21/20 70/81-21/4 10/81-21/28