Answers

Subtract 21/80 from 7/40

7/40 - 21/80 is -7/80.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 40 and 80 is 80
   
   Next, find the equivalent fraction of both fractional numbers with denominator 80
2. For the 1st fraction, since 40 × 2 = 80,
   7/40 = 7 × 2/40 × 2 = 14/80
3. Likewise, for the 2nd fraction, since 80 × 1 = 80,
   21/80 = 21 × 1/80 × 1 = 21/80
4. Subtract the two like fractions:
   14/80 - 21/80 = 14 - 21/80 = -7/80

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