Answers

Subtract 21/45 from 20/84

20/84 - 21/45 is -8/35.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 45 is 1260
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1260
2. For the 1st fraction, since 84 × 15 = 1260,
   20/84 = 20 × 15/84 × 15 = 300/1260
3. Likewise, for the 2nd fraction, since 45 × 28 = 1260,
   21/45 = 21 × 28/45 × 28 = 588/1260
4. Subtract the two like fractions:
   300/1260 - 588/1260 = 300 - 588/1260 = -288/1260
5. After reducing the fraction, the answer is -8/35

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