Subtract 30/81 from 4/12, Solve 4/12

Subtract 30/81 from 4/12

4/12 - 30/81 is -1/27.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 81 is 324

Next, find the equivalent fraction of both fractional numbers with denominator 324
For the 1st fraction, since 12 × 27 = 324,
4/12 = 4 × 27/12 × 27 = 108/324
Likewise, for the 2nd fraction, since 81 × 4 = 324,
30/81 = 30 × 4/81 × 4 = 120/324
Subtract the two like fractions:
108/324 - 120/324 = 108 - 120/324 = -12/324
After reducing the fraction, the answer is -1/27

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