Answers

Subtract 70/42 from 42/80

1^st number: 42/80, 2^nd number: 1 28/42

42/80 - 70/42 is -137/120.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 42 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 80 × 21 = 1680,
   42/80 = 42 × 21/80 × 21 = 882/1680
3. Likewise, for the 2nd fraction, since 42 × 40 = 1680,
   70/42 = 70 × 40/42 × 40 = 2800/1680
4. Subtract the two like fractions:
   882/1680 - 2800/1680 = 882 - 2800/1680 = -1918/1680
5. After reducing the fraction, the answer is -137/120

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