Subtract 21/64 from 40/70, Solve 40/70

Subtract 21/64 from 40/70

40/70 - 21/64 is 109/448.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 64 is 2240

Next, find the equivalent fraction of both fractional numbers with denominator 2240
For the 1st fraction, since 70 × 32 = 2240,
40/70 = 40 × 32/70 × 32 = 1280/2240
Likewise, for the 2nd fraction, since 64 × 35 = 2240,
21/64 = 21 × 35/64 × 35 = 735/2240
Subtract the two like fractions:
1280/2240 - 735/2240 = 1280 - 735/2240 = 545/2240
After reducing the fraction, the answer is 109/448

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