Answers

Subtract 42/90 from 30/84

30/84 - 42/90 is -23/210.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 90 is 1260
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1260
2. For the 1st fraction, since 84 × 15 = 1260,
   30/84 = 30 × 15/84 × 15 = 450/1260
3. Likewise, for the 2nd fraction, since 90 × 14 = 1260,
   42/90 = 42 × 14/90 × 14 = 588/1260
4. Subtract the two like fractions:
   450/1260 - 588/1260 = 450 - 588/1260 = -138/1260
5. After reducing the fraction, the answer is -23/210

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