Answers

Subtract 90/70 from 54/72

1^st number: 54/72, 2^nd number: 1 20/70

54/72 - 90/70 is -15/28.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 70 is 2520
   
   Next, find the equivalent fraction of both fractional numbers with denominator 2520
2. For the 1st fraction, since 72 × 35 = 2520,
   54/72 = 54 × 35/72 × 35 = 1890/2520
3. Likewise, for the 2nd fraction, since 70 × 36 = 2520,
   90/70 = 90 × 36/70 × 36 = 3240/2520
4. Subtract the two like fractions:
   1890/2520 - 3240/2520 = 1890 - 3240/2520 = -1350/2520
5. After reducing the fraction, the answer is -15/28

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