Answers

Subtract 4/8 from 20/42

20/42 - 4/8 is -1/42.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 8 is 168
   
   Next, find the equivalent fraction of both fractional numbers with denominator 168
2. For the 1st fraction, since 42 × 4 = 168,
   20/42 = 20 × 4/42 × 4 = 80/168
3. Likewise, for the 2nd fraction, since 8 × 21 = 168,
   4/8 = 4 × 21/8 × 21 = 84/168
4. Subtract the two like fractions:
   80/168 - 84/168 = 80 - 84/168 = -4/168
5. After reducing the fraction, the answer is -1/42

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