Answers

Subtract 20/21 from 35/80

35/80 - 20/21 is -173/336.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 21 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 80 × 21 = 1680,
   35/80 = 35 × 21/80 × 21 = 735/1680
3. Likewise, for the 2nd fraction, since 21 × 80 = 1680,
   20/21 = 20 × 80/21 × 80 = 1600/1680
4. Subtract the two like fractions:
   735/1680 - 1600/1680 = 735 - 1600/1680 = -865/1680
5. After reducing the fraction, the answer is -173/336

MathStep (Works offline)

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

Related: ⁷⁰/₈₀-²⁰/₂₁ ³⁵/₈₀-⁴⁰/₂₁ ³⁵/₈₀-²⁰/₄₂ ³⁵/₈₀-⁶⁰/₂₁ ³⁵/₈₀-²⁰/₆₃

Subtract Fractions Calculator