Answers

Subtract 72/70 from 81/90

1^st number: 81/90, 2^nd number: 1 2/70

81/90 - 72/70 is -9/70.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 70 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 90 × 7 = 630,
   81/90 = 81 × 7/90 × 7 = 567/630
3. Likewise, for the 2nd fraction, since 70 × 9 = 630,
   72/70 = 72 × 9/70 × 9 = 648/630
4. Subtract the two like fractions:
   567/630 - 648/630 = 567 - 648/630 = -81/630
5. After reducing the fraction, the answer is -9/70

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