Subtract 1/21 from 8/18
8/18 - 1/21 is 25/63.
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,
8/18 = 8 × 7/18 × 7 = 56/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
1/21 = 1 × 6/21 × 6 = 6/126 - Subtract the two like fractions:
56/126 - 6/126 = 56 - 6/126 = 50/126 - After reducing the fraction, the answer is 25/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/18-1/21 8/18-2/21 8/36-1/21 8/18-1/42 24/18-1/21 8/18-3/21 8/54-1/21 8/18-1/63 40/18-1/21 8/18-5/21 8/90-1/21 56/18-1/21 8/18-7/21