Answers

Subtract 72/20 from 45/90

1^st number: 45/90, 2^nd number: 3 12/20

45/90 - 72/20 is -31/10.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 20 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 90 × 2 = 180,
   45/90 = 45 × 2/90 × 2 = 90/180
3. Likewise, for the 2nd fraction, since 20 × 9 = 180,
   72/20 = 72 × 9/20 × 9 = 648/180
4. Subtract the two like fractions:
   90/180 - 648/180 = 90 - 648/180 = -558/180
5. After reducing the fraction, the answer is -31/10

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