Subtract 80/5 from 5/21, Solve 5/21

Subtract 80/5 from 5/21

1^st number: 5/21, 2^nd number: 16 0/5

5/21 - 80/5 is -331/21.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 21 × 5 = 105,
5/21 = 5 × 5/21 × 5 = 25/105
Likewise, for the 2nd fraction, since 5 × 21 = 105,
80/5 = 80 × 21/5 × 21 = 1680/105
Subtract the two like fractions:
25/105 - 1680/105 = 25 - 1680/105 = -1655/105
After reducing the fraction, the answer is -331/21

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