Answers

Subtract 90/45 from 40/42

1^st number: 40/42, 2^nd number: 2 0/45

40/42 - 90/45 is -22/21.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 45 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 42 × 15 = 630,
   40/42 = 40 × 15/42 × 15 = 600/630
3. Likewise, for the 2nd fraction, since 45 × 14 = 630,
   90/45 = 90 × 14/45 × 14 = 1260/630
4. Subtract the two like fractions:
   600/630 - 1260/630 = 600 - 1260/630 = -660/630
5. After reducing the fraction, the answer is -22/21

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