Subtract 81/12 from 27/42
1st number: 27/42, 2nd number: 6 9/12
27/42 - 81/12 is -171/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
27/42 = 27 × 2/42 × 2 = 54/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
81/12 = 81 × 7/12 × 7 = 567/84 - Subtract the two like fractions:
54/84 - 567/84 = 54 - 567/84 = -513/84 - After reducing the fraction, the answer is -171/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 54/42-81/12 27/84-81/12 27/42-81/24 81/42-81/12 27/42-81/36 27/42-81/60 27/42-81/84