Subtract 9/21 from 20/18
1st number: 1 2/18, 2nd number: 9/21
20/18 - 9/21 is 43/63.
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,
20/18 = 20 × 7/18 × 7 = 140/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
9/21 = 9 × 6/21 × 6 = 54/126 - Subtract the two like fractions:
140/126 - 54/126 = 140 - 54/126 = 86/126 - After reducing the fraction, the answer is 43/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/18-9/21 20/18-18/21 20/36-9/21 20/18-9/42 60/18-9/21 20/18-27/21 20/54-9/21 20/18-9/63 20/18-45/21 20/90-9/21 20/18-63/21