Subtract 15/20 from 12/84
12/84 - 15/20 is -17/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
12/84 = 12 × 5/84 × 5 = 60/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
15/20 = 15 × 21/20 × 21 = 315/420 - Subtract the two like fractions:
60/420 - 315/420 = 60 - 315/420 = -255/420 - After reducing the fraction, the answer is -17/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/84-15/20 12/84-30/20 12/84-15/40 36/84-15/20 12/84-45/20 12/84-15/60 60/84-15/20 12/84-75/20