Subtract 84/20 from 16/21, Solve 16/21

Subtract 84/20 from 16/21

1^st number: 16/21, 2^nd number: 4 4/20

16/21 - 84/20 is -361/105.

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,
16/21 = 16 × 20/21 × 20 = 320/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
84/20 = 84 × 21/20 × 21 = 1764/420
Subtract the two like fractions:
320/420 - 1764/420 = 320 - 1764/420 = -1444/420
After reducing the fraction, the answer is -361/105

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