Subtract 6/12 from 8/21
8/21 - 6/12 is -5/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
8/21 = 8 × 4/21 × 4 = 32/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
6/12 = 6 × 7/12 × 7 = 42/84 - Subtract the two like fractions:
32/84 - 42/84 = 32 - 42/84 = -10/84 - After reducing the fraction, the answer is -5/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/21-6/12 8/42-6/12 8/21-6/24 24/21-6/12 8/21-18/12 8/63-6/12 8/21-6/36 40/21-6/12 8/21-30/12 8/21-6/60 56/21-6/12 8/21-42/12 8/21-6/84