Subtract 7/21 from 18/36
18/36 - 7/21 is 1/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 21 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 36 × 7 = 252,
18/36 = 18 × 7/36 × 7 = 126/252 - Likewise, for the 2nd fraction, since 21 × 12 = 252,
7/21 = 7 × 12/21 × 12 = 84/252 - Subtract the two like fractions:
126/252 - 84/252 = 126 - 84/252 = 42/252 - After reducing the fraction, the answer is 1/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/36-14/21 18/72-7/21 18/36-7/42 54/36-7/21 18/36-7/63 90/36-7/21 18/36-35/21 18/36-49/21