Subtract 21/30 from 72/21
1st number: 3 9/21, 2nd number: 21/30
72/21 - 21/30 is 191/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
72/21 = 72 × 10/21 × 10 = 720/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Subtract the two like fractions:
720/210 - 147/210 = 720 - 147/210 = 573/210 - After reducing the fraction, the answer is 191/70
- In mixed form: 251/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/21-42/30 72/42-21/30 72/21-21/60 72/21-63/30 72/63-21/30 72/21-21/90