Subtract 84/21 from 8/5, Solve 1 3/5

Subtract 84/21 from 8/5

1^st number: 1 3/5, 2^nd number: 4 0/21

8/5 - 84/21 is -12/5.

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

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 5 × 21 = 105,
8/5 = 8 × 21/5 × 21 = 168/105
Likewise, for the 2nd fraction, since 21 × 5 = 105,
84/21 = 84 × 5/21 × 5 = 420/105
Subtract the two like fractions:
168/105 - 420/105 = 168 - 420/105 = -252/105
After reducing the fraction, the answer is -12/5

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