Answers

Subtract 20/63 from 20/90

20/90 - 20/63 is -2/21.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 63 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 90 × 7 = 630,
   20/90 = 20 × 7/90 × 7 = 140/630
3. Likewise, for the 2nd fraction, since 63 × 10 = 630,
   20/63 = 20 × 10/63 × 10 = 200/630
4. Subtract the two like fractions:
   140/630 - 200/630 = 140 - 200/630 = -60/630
5. After reducing the fraction, the answer is -2/21

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