Subtract 18/21 from 27/72, Solve 27/72

Subtract 18/21 from 27/72

27/72 - 18/21 is -27/56.

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,
27/72 = 27 × 7/72 × 7 = 189/504
Likewise, for the 2nd fraction, since 21 × 24 = 504,
18/21 = 18 × 24/21 × 24 = 432/504
Subtract the two like fractions:
189/504 - 432/504 = 189 - 432/504 = -243/504
After reducing the fraction, the answer is -27/56

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