Answers

Subtract 90/45 from 2/21

1^st number: 2/21, 2^nd number: 2 0/45

2/21 - 90/45 is -40/21.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 45 is 315
   
   Next, find the equivalent fraction of both fractional numbers with denominator 315
2. For the 1st fraction, since 21 × 15 = 315,
   2/21 = 2 × 15/21 × 15 = 30/315
3. Likewise, for the 2nd fraction, since 45 × 7 = 315,
   90/45 = 90 × 7/45 × 7 = 630/315
4. Subtract the two like fractions:
   30/315 - 630/315 = 30 - 630/315 = -600/315
5. After reducing the fraction, the answer is -40/21

MathStep (Works offline)

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

Related: ⁴/₂₁-⁹⁰/₄₅ ²/₄₂-⁹⁰/₄₅ ⁶/₂₁-⁹⁰/₄₅ ²/₆₃-⁹⁰/₄₅ ¹⁰/₂₁-⁹⁰/₄₅ ¹⁴/₂₁-⁹⁰/₄₅

Subtract Fractions Calculator