Answers

Subtract 21/72 from 90/75

1^st number: 1 15/75, 2^nd number: 21/72

90/75 - 21/72 is 109/120.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 75 and 72 is 1800
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1800
2. For the 1st fraction, since 75 × 24 = 1800,
   90/75 = 90 × 24/75 × 24 = 2160/1800
3. Likewise, for the 2nd fraction, since 72 × 25 = 1800,
   21/72 = 21 × 25/72 × 25 = 525/1800
4. Subtract the two like fractions:
   2160/1800 - 525/1800 = 2160 - 525/1800 = 1635/1800
5. After reducing the fraction, the answer is 109/120

MathStep (Works offline)

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

Related: ⁹⁰/₇₅-⁴²/₇₂ ⁹⁰/₇₅-⁶³/₇₂

Subtract Fractions Calculator