Answers

Subtract 72/81 from 24/42

24/42 - 72/81 is -20/63.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 81 is 1134
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1134
2. For the 1st fraction, since 42 × 27 = 1134,
   24/42 = 24 × 27/42 × 27 = 648/1134
3. Likewise, for the 2nd fraction, since 81 × 14 = 1134,
   72/81 = 72 × 14/81 × 14 = 1008/1134
4. Subtract the two like fractions:
   648/1134 - 1008/1134 = 648 - 1008/1134 = -360/1134
5. After reducing the fraction, the answer is -20/63

MathStep (Works offline)

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

Related: ⁴⁸/₄₂-⁷²/₈₁ ²⁴/₈₄-⁷²/₈₁ ⁷²/₄₂-⁷²/₈₁

Subtract Fractions Calculator