Subtract 8/21 from 72/18
1st number: 4 0/18, 2nd number: 8/21
72/18 - 8/21 is 76/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
72/18 = 72 × 7/18 × 7 = 504/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
8/21 = 8 × 6/21 × 6 = 48/126 - Subtract the two like fractions:
504/126 - 48/126 = 504 - 48/126 = 456/126 - After reducing the fraction, the answer is 76/21
- In mixed form: 313/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/18-16/21 72/36-8/21 72/18-8/42 72/18-24/21 72/54-8/21 72/18-8/63 72/18-40/21 72/90-8/21 72/18-56/21