Subtract 27/18 from 81/42
1st number: 1 39/42, 2nd number: 1 9/18
81/42 - 27/18 is 3/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
81/42 = 81 × 3/42 × 3 = 243/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
27/18 = 27 × 7/18 × 7 = 189/126 - Subtract the two like fractions:
243/126 - 189/126 = 243 - 189/126 = 54/126 - After reducing the fraction, the answer is 3/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/42-54/18 81/84-27/18 81/42-27/36 81/42-81/18 81/42-27/54 81/42-27/90