Subtract 4/36 from 20/21
20/21 - 4/36 is 53/63.
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,
20/21 = 20 × 12/21 × 12 = 240/252 - Likewise, for the 2nd fraction, since 36 × 7 = 252,
4/36 = 4 × 7/36 × 7 = 28/252 - Subtract the two like fractions:
240/252 - 28/252 = 240 - 28/252 = 212/252 - After reducing the fraction, the answer is 53/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/21-4/36 20/21-8/36 20/42-4/36 20/21-4/72 60/21-4/36 20/21-12/36 20/63-4/36 20/21-20/36 20/21-28/36