Answers

Subtract 63/20 from 45/21

1^st number: 2 3/21, 2^nd number: 3 3/20

45/21 - 63/20 is -141/140.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 20 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 21 × 20 = 420,
   45/21 = 45 × 20/21 × 20 = 900/420
3. Likewise, for the 2nd fraction, since 20 × 21 = 420,
   63/20 = 63 × 21/20 × 21 = 1323/420
4. Subtract the two like fractions:
   900/420 - 1323/420 = 900 - 1323/420 = -423/420
5. After reducing the fraction, the answer is -141/140

MathStep (Works offline)

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

Related: ⁹⁰/₂₁-⁶³/₂₀ ⁴⁵/₄₂-⁶³/₂₀ ⁴⁵/₂₁-⁶³/₄₀ ⁴⁵/₆₃-⁶³/₂₀ ⁴⁵/₂₁-⁶³/₆₀

Subtract Fractions Calculator