Answers

Subtract 1/21 from 63/72

63/72 - 1/21 is 139/168.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 21 is 504
   
   Next, find the equivalent fraction of both fractional numbers with denominator 504
2. For the 1st fraction, since 72 × 7 = 504,
   63/72 = 63 × 7/72 × 7 = 441/504
3. Likewise, for the 2nd fraction, since 21 × 24 = 504,
   1/21 = 1 × 24/21 × 24 = 24/504
4. Subtract the two like fractions:
   441/504 - 24/504 = 441 - 24/504 = 417/504
5. After reducing the fraction, the answer is 139/168

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