Answers

Subtract 21/7 from 21/9

1^st number: 2 3/9, 2^nd number: 3 0/7

21/9 - 21/7 is -2/3.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 9 and 7 is 63
   
   Next, find the equivalent fraction of both fractional numbers with denominator 63
2. For the 1st fraction, since 9 × 7 = 63,
   21/9 = 21 × 7/9 × 7 = 147/63
3. Likewise, for the 2nd fraction, since 7 × 9 = 63,
   21/7 = 21 × 9/7 × 9 = 189/63
4. Subtract the two like fractions:
   147/63 - 189/63 = 147 - 189/63 = -42/63
5. After reducing the fraction, the answer is -2/3

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