Answers

Subtract 40/21 from 20/90

1^st number: 20/90, 2^nd number: 1 19/21

20/90 - 40/21 is -106/63.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 21 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 21 × 30 = 630,
   40/21 = 40 × 30/21 × 30 = 1200/630
4. Subtract the two like fractions:
   140/630 - 1200/630 = 140 - 1200/630 = -1060/630
5. After reducing the fraction, the answer is -106/63

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