Subtract 72/21 from 12/3
1st number: 4 0/3, 2nd number: 3 9/21
12/3 - 72/21 is 4/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 3 and 21 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 3 × 7 = 21,
12/3 = 12 × 7/3 × 7 = 84/21 - Likewise, for the 2nd fraction, since 21 × 1 = 21,
72/21 = 72 × 1/21 × 1 = 72/21 - Subtract the two like fractions:
84/21 - 72/21 = 84 - 72/21 = 12/21 - After reducing the fraction, the answer is 4/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/3-72/21 12/6-72/21 12/3-72/42 36/3-72/21 12/9-72/21 12/3-72/63 60/3-72/21 12/15-72/21 84/3-72/21 12/21-72/21