Answers

Subtract 20/21 from 35/40

35/40 - 20/21 is -13/168.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 40 and 21 is 840
   
   Next, find the equivalent fraction of both fractional numbers with denominator 840
2. For the 1st fraction, since 40 × 21 = 840,
   35/40 = 35 × 21/40 × 21 = 735/840
3. Likewise, for the 2nd fraction, since 21 × 40 = 840,
   20/21 = 20 × 40/21 × 40 = 800/840
4. Subtract the two like fractions:
   735/840 - 800/840 = 735 - 800/840 = -65/840
5. After reducing the fraction, the answer is -13/168

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