Subtract 4/12 from 4/21
4/21 - 4/12 is -1/7.
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,
4/21 = 4 × 4/21 × 4 = 16/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
4/12 = 4 × 7/12 × 7 = 28/84 - Subtract the two like fractions:
16/84 - 28/84 = 16 - 28/84 = -12/84 - After reducing the fraction, the answer is -1/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/21-4/12 4/21-8/12 4/42-4/12 4/21-4/24 12/21-4/12 4/63-4/12 4/21-4/36 20/21-4/12 4/21-20/12 4/21-4/60 28/21-4/12 4/21-28/12 4/21-4/84