Subtract 18/21 from 45/64, Solve 45/64

Subtract 18/21 from 45/64

45/64 - 18/21 is -69/448.

Find the least common denominator or LCM of the two denominators:
LCM of 64 and 21 is 1344

Next, find the equivalent fraction of both fractional numbers with denominator 1344
For the 1st fraction, since 64 × 21 = 1344,
45/64 = 45 × 21/64 × 21 = 945/1344
Likewise, for the 2nd fraction, since 21 × 64 = 1344,
18/21 = 18 × 64/21 × 64 = 1152/1344
Subtract the two like fractions:
945/1344 - 1152/1344 = 945 - 1152/1344 = -207/1344
After reducing the fraction, the answer is -69/448

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