Subtract 18/81 from 15/42
15/42 - 18/81 is 17/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 81 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 42 × 27 = 1134,
15/42 = 15 × 27/42 × 27 = 405/1134 - Likewise, for the 2nd fraction, since 81 × 14 = 1134,
18/81 = 18 × 14/81 × 14 = 252/1134 - Subtract the two like fractions:
405/1134 - 252/1134 = 405 - 252/1134 = 153/1134 - After reducing the fraction, the answer is 17/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/42-18/81 15/42-36/81 15/84-18/81 45/42-18/81 15/42-54/81 75/42-18/81 15/42-90/81