Subtract 20/21 from 1/12
1/12 - 20/21 is -73/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
1/12 = 1 × 7/12 × 7 = 7/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
20/21 = 20 × 4/21 × 4 = 80/84 - Subtract the two like fractions:
7/84 - 80/84 = 7 - 80/84 = -73/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/12-20/21 1/12-40/21 1/24-20/21 1/12-20/42 3/12-20/21 1/12-60/21 1/36-20/21 1/12-20/63 5/12-20/21 1/60-20/21 7/12-20/21 1/84-20/21