Subtract 45/54 from 21/30, Solve 21/30

Subtract 45/54 from 21/30

21/30 - 45/54 is -2/15.

Find the least common denominator or LCM of the two denominators:
LCM of 30 and 54 is 270

Next, find the equivalent fraction of both fractional numbers with denominator 270
For the 1st fraction, since 30 × 9 = 270,
21/30 = 21 × 9/30 × 9 = 189/270
Likewise, for the 2nd fraction, since 54 × 5 = 270,
45/54 = 45 × 5/54 × 5 = 225/270
Subtract the two like fractions:
189/270 - 225/270 = 189 - 225/270 = -36/270
After reducing the fraction, the answer is -2/15

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