Subtract 21/7 from 1/72, Solve 1/72

Subtract 21/7 from 1/72

1^st number: 1/72, 2^nd number: 3 0/7

1/72 - 21/7 is -215/72.

Find the least common denominator or LCM of the two denominators:
LCM of 72 and 7 is 504

Next, find the equivalent fraction of both fractional numbers with denominator 504
For the 1st fraction, since 72 × 7 = 504,
1/72 = 1 × 7/72 × 7 = 7/504
Likewise, for the 2nd fraction, since 7 × 72 = 504,
21/7 = 21 × 72/7 × 72 = 1512/504
Subtract the two like fractions:
7/504 - 1512/504 = 7 - 1512/504 = -1505/504
After reducing the fraction, the answer is -215/72

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