Subtract 56/18 from 8/21
1st number: 8/21, 2nd number: 3 2/18
8/21 - 56/18 is -172/63.
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,
8/21 = 8 × 6/21 × 6 = 48/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
56/18 = 56 × 7/18 × 7 = 392/126 - Subtract the two like fractions:
48/126 - 392/126 = 48 - 392/126 = -344/126 - After reducing the fraction, the answer is -172/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/21-56/18 8/42-56/18 8/21-56/36 24/21-56/18 8/63-56/18 8/21-56/54 40/21-56/18 8/21-56/90 56/21-56/18