Subtract 30/81 from 12/45, Solve 12/45

Subtract 30/81 from 12/45

12/45 - 30/81 is -14/135.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 81 is 405

Next, find the equivalent fraction of both fractional numbers with denominator 405
For the 1st fraction, since 45 × 9 = 405,
12/45 = 12 × 9/45 × 9 = 108/405
Likewise, for the 2nd fraction, since 81 × 5 = 405,
30/81 = 30 × 5/81 × 5 = 150/405
Subtract the two like fractions:
108/405 - 150/405 = 108 - 150/405 = -42/405
After reducing the fraction, the answer is -14/135

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