Subtract 5/20 from 49/21, Solve 2 7/21

Subtract 5/20 from 49/21

1^st number: 2 7/21, 2^nd number: 5/20

49/21 - 5/20 is 25/12.

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,
49/21 = 49 × 20/21 × 20 = 980/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
5/20 = 5 × 21/20 × 21 = 105/420
Subtract the two like fractions:
980/420 - 105/420 = 980 - 105/420 = 875/420
After reducing the fraction, the answer is 25/12
In mixed form: 21/12

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad