Subtract 3/7 from 72/21
1st number: 3 9/21, 2nd number: 3/7
72/21 - 3/7 is 3/1.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
72/21 = 72 × 1/21 × 1 = 72/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
3/7 = 3 × 3/7 × 3 = 9/21 - Subtract the two like fractions:
72/21 - 9/21 = 72 - 9/21 = 63/21 - After reducing the fraction, the answer is 3/1
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/21-6/7 72/42-3/7 72/21-3/14 72/21-9/7 72/63-3/7 72/21-3/21 72/21-15/7 72/21-3/35 72/21-21/7 72/21-3/49