Answers

Subtract 24/20 from 81/90

1^st number: 81/90, 2^nd number: 1 4/20

81/90 - 24/20 is -3/10.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 20 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 90 × 2 = 180,
   81/90 = 81 × 2/90 × 2 = 162/180
3. Likewise, for the 2nd fraction, since 20 × 9 = 180,
   24/20 = 24 × 9/20 × 9 = 216/180
4. Subtract the two like fractions:
   162/180 - 216/180 = 162 - 216/180 = -54/180
5. After reducing the fraction, the answer is -3/10

MathStep (Works offline)

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

Related: ⁸¹/₉₀-⁴⁸/₂₀ ⁸¹/₉₀-²⁴/₄₀ ⁸¹/₉₀-⁷²/₂₀ ⁸¹/₉₀-²⁴/₆₀

Subtract Fractions Calculator