Subtract 18/21 from 15/54
15/54 - 18/21 is -73/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 21 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
15/54 = 15 × 7/54 × 7 = 105/378 - Likewise, for the 2nd fraction, since 21 × 18 = 378,
18/21 = 18 × 18/21 × 18 = 324/378 - Subtract the two like fractions:
105/378 - 324/378 = 105 - 324/378 = -219/378 - After reducing the fraction, the answer is -73/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/54-18/21 15/54-36/21 15/54-18/42 45/54-18/21 15/54-54/21 15/54-18/63 75/54-18/21 15/54-90/21