Answers

Subtract 40/42 from 40/72

40/72 - 40/42 is -25/63.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 42 is 504
   
   Next, find the equivalent fraction of both fractional numbers with denominator 504
2. For the 1st fraction, since 72 × 7 = 504,
   40/72 = 40 × 7/72 × 7 = 280/504
3. Likewise, for the 2nd fraction, since 42 × 12 = 504,
   40/42 = 40 × 12/42 × 12 = 480/504
4. Subtract the two like fractions:
   280/504 - 480/504 = 280 - 480/504 = -200/504
5. After reducing the fraction, the answer is -25/63

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