Answers

Subtract 90/45 from 20/63

1^st number: 20/63, 2^nd number: 2 0/45

20/63 - 90/45 is -106/63.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 63 and 45 is 315
   
   Next, find the equivalent fraction of both fractional numbers with denominator 315
2. For the 1st fraction, since 63 × 5 = 315,
   20/63 = 20 × 5/63 × 5 = 100/315
3. Likewise, for the 2nd fraction, since 45 × 7 = 315,
   90/45 = 90 × 7/45 × 7 = 630/315
4. Subtract the two like fractions:
   100/315 - 630/315 = 100 - 630/315 = -530/315
5. After reducing the fraction, the answer is -106/63

MathStep (Works offline)

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

Related: ⁴⁰/₆₃-⁹⁰/₄₅ ⁶⁰/₆₃-⁹⁰/₄₅

Subtract Fractions Calculator