Answers

Subtract 7/18 from 8/21

8/21 - 7/18 is -1/126.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 18 is 126
   
   Next, find the equivalent fraction of both fractional numbers with denominator 126
2. For the 1st fraction, since 21 × 6 = 126,
   8/21 = 8 × 6/21 × 6 = 48/126
3. Likewise, for the 2nd fraction, since 18 × 7 = 126,
   7/18 = 7 × 7/18 × 7 = 49/126
4. Subtract the two like fractions:
   48/126 - 49/126 = 48 - 49/126 = -1/126

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