Answers

Subtract 80/21 from 35/72

1^st number: 35/72, 2^nd number: 3 17/21

35/72 - 80/21 is -1675/504.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 21 is 504
   
   Next, find the equivalent fraction of both fractional numbers with denominator 504
2. For the 1st fraction, since 72 × 7 = 504,
   35/72 = 35 × 7/72 × 7 = 245/504
3. Likewise, for the 2nd fraction, since 21 × 24 = 504,
   80/21 = 80 × 24/21 × 24 = 1920/504
4. Subtract the two like fractions:
   245/504 - 1920/504 = 245 - 1920/504 = -1675/504

MathStep (Works offline)

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

Related: ⁷⁰/₇₂-⁸⁰/₂₁ ³⁵/₇₂-⁸⁰/₄₂ ³⁵/₇₂-⁸⁰/₆₃

Subtract Fractions Calculator