Answers

Subtract 45/90 from 20/49

20/49 - 45/90 is -9/98.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 49 and 90 is 4410
   
   Next, find the equivalent fraction of both fractional numbers with denominator 4410
2. For the 1st fraction, since 49 × 90 = 4410,
   20/49 = 20 × 90/49 × 90 = 1800/4410
3. Likewise, for the 2nd fraction, since 90 × 49 = 4410,
   45/90 = 45 × 49/90 × 49 = 2205/4410
4. Subtract the two like fractions:
   1800/4410 - 2205/4410 = 1800 - 2205/4410 = -405/4410
5. After reducing the fraction, the answer is -9/98

MathStep (Works offline)

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

Related: ⁴⁰/₄₉-⁴⁵/₉₀ ²⁰/₉₈-⁴⁵/₉₀ ⁶⁰/₄₉-⁴⁵/₉₀

Subtract Fractions Calculator