Subtract 63/21 from 72/20
1st number: 3 12/20, 2nd number: 3 0/21
72/20 - 63/21 is 3/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
63/21 = 63 × 20/21 × 20 = 1260/420 - Subtract the two like fractions:
1512/420 - 1260/420 = 1512 - 1260/420 = 252/420 - After reducing the fraction, the answer is 3/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/40-63/21 72/20-63/42 72/60-63/21