Subtract 80/21 from 10/72, Solve 10/72

Subtract 80/21 from 10/72

1^st number: 10/72, 2^nd number: 3 17/21

10/72 - 80/21 is -925/252.

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,
10/72 = 10 × 7/72 × 7 = 70/504
Likewise, for the 2nd fraction, since 21 × 24 = 504,
80/21 = 80 × 24/21 × 24 = 1920/504
Subtract the two like fractions:
70/504 - 1920/504 = 70 - 1920/504 = -1850/504
After reducing the fraction, the answer is -925/252

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