Answers

Subtract 42/45 from 90/20

1^st number: 4 10/20, 2^nd number: 42/45

90/20 - 42/45 is 107/30.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 45 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 20 × 9 = 180,
   90/20 = 90 × 9/20 × 9 = 810/180
3. Likewise, for the 2nd fraction, since 45 × 4 = 180,
   42/45 = 42 × 4/45 × 4 = 168/180
4. Subtract the two like fractions:
   810/180 - 168/180 = 810 - 168/180 = 642/180
5. After reducing the fraction, the answer is 107/30
6. In mixed form: 317/30

MathStep (Works offline)

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

Related: ⁹⁰/₂₀-⁸⁴/₄₅ ⁹⁰/₄₀-⁴²/₄₅ ⁹⁰/₂₀-⁴²/₉₀ ⁹⁰/₆₀-⁴²/₄₅

Subtract Fractions Calculator