Subtract 12/21 from 21/36
21/36 - 12/21 is 1/84.
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,
21/36 = 21 × 7/36 × 7 = 147/252 - Likewise, for the 2nd fraction, since 21 × 12 = 252,
12/21 = 12 × 12/21 × 12 = 144/252 - Subtract the two like fractions:
147/252 - 144/252 = 147 - 144/252 = 3/252 - After reducing the fraction, the answer is 1/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/36-12/21 21/36-24/21 21/72-12/21 21/36-12/42 63/36-12/21 21/36-36/21 21/36-12/63 21/36-60/21 21/36-84/21