Answers

Subtract 21/90 from 15/75

15/75 - 21/90 is -1/30.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 75 and 90 is 450
   
   Next, find the equivalent fraction of both fractional numbers with denominator 450
2. For the 1st fraction, since 75 × 6 = 450,
   15/75 = 15 × 6/75 × 6 = 90/450
3. Likewise, for the 2nd fraction, since 90 × 5 = 450,
   21/90 = 21 × 5/90 × 5 = 105/450
4. Subtract the two like fractions:
   90/450 - 105/450 = 90 - 105/450 = -15/450
5. After reducing the fraction, the answer is -1/30

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