Subtract 27/20 from 7/21
1st number: 7/21, 2nd number: 1 7/20
7/21 - 27/20 is -61/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
7/21 = 7 × 20/21 × 20 = 140/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
27/20 = 27 × 21/20 × 21 = 567/420 - Subtract the two like fractions:
140/420 - 567/420 = 140 - 567/420 = -427/420 - After reducing the fraction, the answer is -61/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-27/20 7/21-54/20 7/42-27/20 7/21-27/40 7/21-81/20 7/63-27/20 7/21-27/60 35/21-27/20 49/21-27/20