Subtract 4/72 from 1/42, Solve 1/42

Subtract 4/72 from 1/42

1/42 - 4/72 is -2/63.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504

Next, find the equivalent fraction of both fractional numbers with denominator 504
For the 1st fraction, since 42 × 12 = 504,
1/42 = 1 × 12/42 × 12 = 12/504
Likewise, for the 2nd fraction, since 72 × 7 = 504,
4/72 = 4 × 7/72 × 7 = 28/504
Subtract the two like fractions:
12/504 - 28/504 = 12 - 28/504 = -16/504
After reducing the fraction, the answer is -2/63

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