Subtract 8/45 from 72/21
1st number: 3 9/21, 2nd number: 8/45
72/21 - 8/45 is 1024/315.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
72/21 = 72 × 15/21 × 15 = 1080/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
8/45 = 8 × 7/45 × 7 = 56/315 - Subtract the two like fractions:
1080/315 - 56/315 = 1080 - 56/315 = 1024/315 - In mixed form: 379/315
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/21-16/45 72/42-8/45 72/21-8/90 72/21-24/45 72/63-8/45 72/21-40/45 72/21-56/45