Subtract 15/18 from 21/36
21/36 - 15/18 is -1/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 18 is 36
Next, find the equivalent fraction of both fractional numbers with denominator 36 - For the 1st fraction, since 36 × 1 = 36,
21/36 = 21 × 1/36 × 1 = 21/36 - Likewise, for the 2nd fraction, since 18 × 2 = 36,
15/18 = 15 × 2/18 × 2 = 30/36 - Subtract the two like fractions:
21/36 - 30/36 = 21 - 30/36 = -9/36 - After reducing the fraction, the answer is -1/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/36-15/18 21/36-30/18 21/72-15/18 21/36-15/36 63/36-15/18 21/36-45/18 21/36-15/54 21/36-75/18 21/36-15/90