Answers

Subtract 5/21 from 3/20

3/20 - 5/21 is -37/420.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 21 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 20 × 21 = 420,
   3/20 = 3 × 21/20 × 21 = 63/420
3. Likewise, for the 2nd fraction, since 21 × 20 = 420,
   5/21 = 5 × 20/21 × 20 = 100/420
4. Subtract the two like fractions:
   63/420 - 100/420 = 63 - 100/420 = -37/420

MathStep (Works offline)

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

Related: ⁶/₂₀-⁵/₂₁ ³/₂₀-¹⁰/₂₁ ³/₄₀-⁵/₂₁ ³/₂₀-⁵/₄₂ ⁹/₂₀-⁵/₂₁ ³/₂₀-¹⁵/₂₁ ³/₆₀-⁵/₂₁ ³/₂₀-⁵/₆₃ ¹⁵/₂₀-⁵/₂₁ ³/₂₀-²⁵/₂₁ ²¹/₂₀-⁵/₂₁ ³/₂₀-³⁵/₂₁

Subtract Fractions Calculator