Add 12/21 and 42/12, Solve 12/21 + 3 6/12 as a fraction

Add 12/21 and 42/12

1^st number: 12/21, 2^nd number: 3 6/12

12/21 + 42/12 is 57/14.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 21 × 4 = 84,
12/21 = 12 × 4/21 × 4 = 48/84
Likewise, for the 2nd fraction, since 12 × 7 = 84,
42/12 = 42 × 7/12 × 7 = 294/84
Add the two like fractions:
48/84 + 294/84 = 48 + 294/84 = 342/84
342/84 simplified gives 57/14
So, 12/21 + 42/12 = 57/14
In mixed form: 41/14

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