Answers

Subtract 1/21 from 42/54

42/54 - 1/21 is 46/63.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 54 and 21 is 378
   
   Next, find the equivalent fraction of both fractional numbers with denominator 378
2. For the 1st fraction, since 54 × 7 = 378,
   42/54 = 42 × 7/54 × 7 = 294/378
3. Likewise, for the 2nd fraction, since 21 × 18 = 378,
   1/21 = 1 × 18/21 × 18 = 18/378
4. Subtract the two like fractions:
   294/378 - 18/378 = 294 - 18/378 = 276/378
5. After reducing the fraction, the answer is 46/63

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