Answers

Subtract 80/49 from 20/81

1^st number: 20/81, 2^nd number: 1 31/49

20/81 - 80/49 is -5500/3969.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 49 is 3969
   
   Next, find the equivalent fraction of both fractional numbers with denominator 3969
2. For the 1st fraction, since 81 × 49 = 3969,
   20/81 = 20 × 49/81 × 49 = 980/3969
3. Likewise, for the 2nd fraction, since 49 × 81 = 3969,
   80/49 = 80 × 81/49 × 81 = 6480/3969
4. Subtract the two like fractions:
   980/3969 - 6480/3969 = 980 - 6480/3969 = -5500/3969

MathStep (Works offline)

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

Related: ⁴⁰/₈₁-⁸⁰/₄₉ ²⁰/₈₁-⁸⁰/₉₈ ⁶⁰/₈₁-⁸⁰/₄₉

Subtract Fractions Calculator