Subtract 81/21 from 3/6
1st number: 3/6, 2nd number: 3 18/21
3/6 - 81/21 is -47/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 6 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 6 × 7 = 42,
3/6 = 3 × 7/6 × 7 = 21/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
81/21 = 81 × 2/21 × 2 = 162/42 - Subtract the two like fractions:
21/42 - 162/42 = 21 - 162/42 = -141/42 - After reducing the fraction, the answer is -47/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 3/12-81/21 3/6-81/42 9/6-81/21 3/18-81/21 3/6-81/63 15/6-81/21 3/30-81/21 21/6-81/21 3/42-81/21