Subtract 35/80 from 42/21, Solve 2 0/21

Subtract 35/80 from 42/21

1^st number: 2 0/21, 2^nd number: 35/80

42/21 - 35/80 is 25/16.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
42/21 = 42 × 80/21 × 80 = 3360/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
35/80 = 35 × 21/80 × 21 = 735/1680
Subtract the two like fractions:
3360/1680 - 735/1680 = 3360 - 735/1680 = 2625/1680
After reducing the fraction, the answer is 25/16
In mixed form: 19/16

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