Add 72/21 and 84/24, Solve 3 9/21 + 3 12/24 as a fraction

Add 72/21 and 84/24

1^st number: 3 9/21, 2^nd number: 3 12/24

72/21 + 84/24 is 97/14.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 24 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 21 × 8 = 168,
72/21 = 72 × 8/21 × 8 = 576/168
Likewise, for the 2nd fraction, since 24 × 7 = 168,
84/24 = 84 × 7/24 × 7 = 588/168
Add the two like fractions:
576/168 + 588/168 = 576 + 588/168 = 1164/168
1164/168 simplified gives 97/14
So, 72/21 + 84/24 = 97/14
In mixed form: 613/14

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