Answers

Subtract 80/21 from 50/81

1^st number: 50/81, 2^nd number: 3 17/21

50/81 - 80/21 is -1810/567.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 21 is 567
   
   Next, find the equivalent fraction of both fractional numbers with denominator 567
2. For the 1st fraction, since 81 × 7 = 567,
   50/81 = 50 × 7/81 × 7 = 350/567
3. Likewise, for the 2nd fraction, since 21 × 27 = 567,
   80/21 = 80 × 27/21 × 27 = 2160/567
4. Subtract the two like fractions:
   350/567 - 2160/567 = 350 - 2160/567 = -1810/567

MathStep (Works offline)

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

Related: ⁵⁰/₈₁-⁸⁰/₄₂ ⁵⁰/₈₁-⁸⁰/₆₃

Subtract Fractions Calculator