Answers

Subtract 30/50 from 21/90

21/90 - 30/50 is -11/30.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 50 is 450
   
   Next, find the equivalent fraction of both fractional numbers with denominator 450
2. For the 1st fraction, since 90 × 5 = 450,
   21/90 = 21 × 5/90 × 5 = 105/450
3. Likewise, for the 2nd fraction, since 50 × 9 = 450,
   30/50 = 30 × 9/50 × 9 = 270/450
4. Subtract the two like fractions:
   105/450 - 270/450 = 105 - 270/450 = -165/450
5. After reducing the fraction, the answer is -11/30

MathStep (Works offline)

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

Related: ⁴²/₉₀-³⁰/₅₀ ²¹/₉₀-⁶⁰/₅₀ ⁶³/₉₀-³⁰/₅₀ ²¹/₉₀-⁹⁰/₅₀

Subtract Fractions Calculator