Answers

Subtract 63/90 from 28/21

1^st number: 1 7/21, 2^nd number: 63/90

28/21 - 63/90 is 19/30.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 90 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 21 × 30 = 630,
   28/21 = 28 × 30/21 × 30 = 840/630
3. Likewise, for the 2nd fraction, since 90 × 7 = 630,
   63/90 = 63 × 7/90 × 7 = 441/630
4. Subtract the two like fractions:
   840/630 - 441/630 = 840 - 441/630 = 399/630
5. After reducing the fraction, the answer is 19/30

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