Subtract 3/18 from 4/21
4/21 - 3/18 is 1/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
4/21 = 4 × 6/21 × 6 = 24/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
3/18 = 3 × 7/18 × 7 = 21/126 - Subtract the two like fractions:
24/126 - 21/126 = 24 - 21/126 = 3/126 - After reducing the fraction, the answer is 1/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/21-3/18 4/21-6/18 4/42-3/18 4/21-3/36 12/21-3/18 4/21-9/18 4/63-3/18 4/21-3/54 20/21-3/18 4/21-15/18 4/21-3/90 28/21-3/18 4/21-21/18