Subtract 80/21 from 15/12
1st number: 1 3/12, 2nd number: 3 17/21
15/12 - 80/21 is -215/84.
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,
15/12 = 15 × 7/12 × 7 = 105/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
80/21 = 80 × 4/21 × 4 = 320/84 - Subtract the two like fractions:
105/84 - 320/84 = 105 - 320/84 = -215/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/12-80/21 15/24-80/21 15/12-80/42 45/12-80/21 15/36-80/21 15/12-80/63 75/12-80/21 15/60-80/21 15/84-80/21