Subtract 1/21 from 9/72, Solve 9/72

Subtract 1/21 from 9/72

9/72 - 1/21 is 13/168.

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
For the 1st fraction, since 72 × 7 = 504,
9/72 = 9 × 7/72 × 7 = 63/504
Likewise, for the 2nd fraction, since 21 × 24 = 504,
1/21 = 1 × 24/21 × 24 = 24/504
Subtract the two like fractions:
63/504 - 24/504 = 63 - 24/504 = 39/504
After reducing the fraction, the answer is 13/168

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