Answers

Subtract 21/30 from 42/84

42/84 - 21/30 is -1/5.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 30 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 84 × 5 = 420,
   42/84 = 42 × 5/84 × 5 = 210/420
3. Likewise, for the 2nd fraction, since 30 × 14 = 420,
   21/30 = 21 × 14/30 × 14 = 294/420
4. Subtract the two like fractions:
   210/420 - 294/420 = 210 - 294/420 = -84/420
5. After reducing the fraction, the answer is -1/5

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