Subtract 20/7 from 21/84
1st number: 21/84, 2nd number: 2 6/7
21/84 - 20/7 is -73/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 7 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 84 × 1 = 84,
21/84 = 21 × 1/84 × 1 = 21/84 - Likewise, for the 2nd fraction, since 7 × 12 = 84,
20/7 = 20 × 12/7 × 12 = 240/84 - Subtract the two like fractions:
21/84 - 240/84 = 21 - 240/84 = -219/84 - After reducing the fraction, the answer is -73/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84-20/7 21/84-40/7 21/84-20/14 63/84-20/7 21/84-60/7 21/84-20/21 21/84-20/35 21/84-20/49