Answers

Subtract 4/90 from 42/80

42/80 - 4/90 is 173/360.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 90 is 720
   
   Next, find the equivalent fraction of both fractional numbers with denominator 720
2. For the 1st fraction, since 80 × 9 = 720,
   42/80 = 42 × 9/80 × 9 = 378/720
3. Likewise, for the 2nd fraction, since 90 × 8 = 720,
   4/90 = 4 × 8/90 × 8 = 32/720
4. Subtract the two like fractions:
   378/720 - 32/720 = 378 - 32/720 = 346/720
5. After reducing the fraction, the answer is 173/360

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