Subtract 18/36 from 15/21
15/21 - 18/36 is 3/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 36 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 21 × 12 = 252,
15/21 = 15 × 12/21 × 12 = 180/252 - Likewise, for the 2nd fraction, since 36 × 7 = 252,
18/36 = 18 × 7/36 × 7 = 126/252 - Subtract the two like fractions:
180/252 - 126/252 = 180 - 126/252 = 54/252 - After reducing the fraction, the answer is 3/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21-18/36 15/42-18/36 15/21-18/72 45/21-18/36 15/21-54/36 15/63-18/36 75/21-18/36 15/21-90/36