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