Subtract 30/64 from 7/21, Solve 7/21

Subtract 30/64 from 7/21

7/21 - 30/64 is -13/96.

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

Next, find the equivalent fraction of both fractional numbers with denominator 1344
For the 1st fraction, since 21 × 64 = 1344,
7/21 = 7 × 64/21 × 64 = 448/1344
Likewise, for the 2nd fraction, since 64 × 21 = 1344,
30/64 = 30 × 21/64 × 21 = 630/1344
Subtract the two like fractions:
448/1344 - 630/1344 = 448 - 630/1344 = -182/1344
After reducing the fraction, the answer is -13/96

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