Subtract 28/20 from 64/21, Solve 3 1/21

Subtract 28/20 from 64/21

1^st number: 3 1/21, 2^nd number: 1 8/20

64/21 - 28/20 is 173/105.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 21 × 20 = 420,
64/21 = 64 × 20/21 × 20 = 1280/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
28/20 = 28 × 21/20 × 21 = 588/420
Subtract the two like fractions:
1280/420 - 588/420 = 1280 - 588/420 = 692/420
After reducing the fraction, the answer is 173/105
In mixed form: 168/105

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