Add 12/21 and 42/27, Solve 12/21 + 1 15/27 as a fraction

Add 12/21 and 42/27

1^st number: 12/21, 2^nd number: 1 15/27

12/21 + 42/27 is 134/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 27 is 189

Next, find the equivalent fraction of both fractional numbers with denominator 189
For the 1st fraction, since 21 × 9 = 189,
12/21 = 12 × 9/21 × 9 = 108/189
Likewise, for the 2nd fraction, since 27 × 7 = 189,
42/27 = 42 × 7/27 × 7 = 294/189
Add the two like fractions:
108/189 + 294/189 = 108 + 294/189 = 402/189
402/189 simplified gives 134/63
So, 12/21 + 42/27 = 134/63
In mixed form: 28/63

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