Add 9/12 and 81/42, Solve 9/12 + 1 39/42 as a fraction

Add 9/12 and 81/42

1^st number: 9/12, 2^nd number: 1 39/42

9/12 + 81/42 is 75/28.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 42 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
9/12 = 9 × 7/12 × 7 = 63/84
Likewise, for the 2nd fraction, since 42 × 2 = 84,
81/42 = 81 × 2/42 × 2 = 162/84
Add the two like fractions:
63/84 + 162/84 = 63 + 162/84 = 225/84
225/84 simplified gives 75/28
So, 9/12 + 81/42 = 75/28
In mixed form: 219/28

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