Add 6/8 and 81/21, Solve 6/8 + 3 18/21 as a fraction

Add 6/8 and 81/21

1^st number: 6/8, 2^nd number: 3 18/21

6/8 + 81/21 is 129/28.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 8 × 21 = 168,
6/8 = 6 × 21/8 × 21 = 126/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
81/21 = 81 × 8/21 × 8 = 648/168
Add the two like fractions:
126/168 + 648/168 = 126 + 648/168 = 774/168
774/168 simplified gives 129/28
So, 6/8 + 81/21 = 129/28
In mixed form: 417/28

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