Subtract 63/21 from 9/72, Solve 9/72

Subtract 63/21 from 9/72

1^st number: 9/72, 2^nd number: 3 0/21

9/72 - 63/21 is -23/8.

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,
63/21 = 63 × 24/21 × 24 = 1512/504
Subtract the two like fractions:
63/504 - 1512/504 = 63 - 1512/504 = -1449/504
After reducing the fraction, the answer is -23/8

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