Answers

Subtract 35/40 from 21/42

21/42 - 35/40 is -3/8.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 40 is 840
   
   Next, find the equivalent fraction of both fractional numbers with denominator 840
2. For the 1st fraction, since 42 × 20 = 840,
   21/42 = 21 × 20/42 × 20 = 420/840
3. Likewise, for the 2nd fraction, since 40 × 21 = 840,
   35/40 = 35 × 21/40 × 21 = 735/840
4. Subtract the two like fractions:
   420/840 - 735/840 = 420 - 735/840 = -315/840
5. After reducing the fraction, the answer is -3/8

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