Answers

Subtract 21/20 from 28/18

1^st number: 1 10/18, 2^nd number: 1 1/20

28/18 - 21/20 is 91/180.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 18 and 20 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 18 × 10 = 180,
   28/18 = 28 × 10/18 × 10 = 280/180
3. Likewise, for the 2nd fraction, since 20 × 9 = 180,
   21/20 = 21 × 9/20 × 9 = 189/180
4. Subtract the two like fractions:
   280/180 - 189/180 = 280 - 189/180 = 91/180

MathStep (Works offline)

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

Related: ⁵⁶/₁₈-²¹/₂₀ ²⁸/₁₈-⁴²/₂₀ ²⁸/₃₆-²¹/₂₀ ²⁸/₁₈-²¹/₄₀ ⁸⁴/₁₈-²¹/₂₀ ²⁸/₁₈-⁶³/₂₀ ²⁸/₅₄-²¹/₂₀ ²⁸/₁₈-²¹/₆₀ ²⁸/₉₀-²¹/₂₀

Subtract Fractions Calculator