Subtract 21/54 from 20/84
20/84 - 21/54 is -19/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 54 is 756
Next, find the equivalent fraction of both fractional numbers with denominator 756 - For the 1st fraction, since 84 × 9 = 756,
20/84 = 20 × 9/84 × 9 = 180/756 - Likewise, for the 2nd fraction, since 54 × 14 = 756,
21/54 = 21 × 14/54 × 14 = 294/756 - Subtract the two like fractions:
180/756 - 294/756 = 180 - 294/756 = -114/756 - After reducing the fraction, the answer is -19/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/84-21/54 20/84-42/54 60/84-21/54 20/84-63/54