Add 18/21 and 15/42, Solve 18/21 + 15/42 as a fraction

Add 18/21 and 15/42

18/21 + 15/42 is 17/14.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42

Next, find the equivalent fraction of both fractional numbers with denominator 42
For the 1st fraction, since 21 × 2 = 42,
18/21 = 18 × 2/21 × 2 = 36/42
Likewise, for the 2nd fraction, since 42 × 1 = 42,
15/42 = 15 × 1/42 × 1 = 15/42
Add the two like fractions:
36/42 + 15/42 = 36 + 15/42 = 51/42
51/42 simplified gives 17/14
So, 18/21 + 15/42 = 17/14
In mixed form: 13/14

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