Subtract 21/36 from 18/21
18/21 - 21/36 is 23/84.
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,
18/21 = 18 × 12/21 × 12 = 216/252 - Likewise, for the 2nd fraction, since 36 × 7 = 252,
21/36 = 21 × 7/36 × 7 = 147/252 - Subtract the two like fractions:
216/252 - 147/252 = 216 - 147/252 = 69/252 - After reducing the fraction, the answer is 23/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21-21/36 18/21-42/36 18/42-21/36 18/21-21/72 54/21-21/36 18/21-63/36 18/63-21/36 90/21-21/36