Answers

Subtract 90/21 from 54/64

1^st number: 54/64, 2^nd number: 4 6/21

54/64 - 90/21 is -771/224.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 64 and 21 is 1344
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1344
2. For the 1st fraction, since 64 × 21 = 1344,
   54/64 = 54 × 21/64 × 21 = 1134/1344
3. Likewise, for the 2nd fraction, since 21 × 64 = 1344,
   90/21 = 90 × 64/21 × 64 = 5760/1344
4. Subtract the two like fractions:
   1134/1344 - 5760/1344 = 1134 - 5760/1344 = -4626/1344
5. After reducing the fraction, the answer is -771/224

MathStep (Works offline)

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

Related: ⁵⁴/₆₄-⁹⁰/₄₂ ⁵⁴/₆₄-⁹⁰/₆₃

Subtract Fractions Calculator