Subtract 7/64 from 21/42, Solve 21/42

Subtract 7/64 from 21/42

21/42 - 7/64 is 25/64.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 64 is 1344

Next, find the equivalent fraction of both fractional numbers with denominator 1344
For the 1st fraction, since 42 × 32 = 1344,
21/42 = 21 × 32/42 × 32 = 672/1344
Likewise, for the 2nd fraction, since 64 × 21 = 1344,
7/64 = 7 × 21/64 × 21 = 147/1344
Subtract the two like fractions:
672/1344 - 147/1344 = 672 - 147/1344 = 525/1344
After reducing the fraction, the answer is 25/64

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