Answers

Subtract 30/72 from 30/90

30/90 - 30/72 is -1/12.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 72 is 360
   
   Next, find the equivalent fraction of both fractional numbers with denominator 360
2. For the 1st fraction, since 90 × 4 = 360,
   30/90 = 30 × 4/90 × 4 = 120/360
3. Likewise, for the 2nd fraction, since 72 × 5 = 360,
   30/72 = 30 × 5/72 × 5 = 150/360
4. Subtract the two like fractions:
   120/360 - 150/360 = 120 - 150/360 = -30/360
5. After reducing the fraction, the answer is -1/12

MathStep (Works offline)

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

Related: ⁶⁰/₉₀-³⁰/₇₂ ³⁰/₉₀-⁶⁰/₇₂ ³⁰/₉₀-⁹⁰/₇₂

Subtract Fractions Calculator