Answers

Subtract 1/63 from 21/72

21/72 - 1/63 is 139/504.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 63 is 504
   
   Next, find the equivalent fraction of both fractional numbers with denominator 504
2. For the 1st fraction, since 72 × 7 = 504,
   21/72 = 21 × 7/72 × 7 = 147/504
3. Likewise, for the 2nd fraction, since 63 × 8 = 504,
   1/63 = 1 × 8/63 × 8 = 8/504
4. Subtract the two like fractions:
   147/504 - 8/504 = 147 - 8/504 = 139/504

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