Add 15/18 and 63/42, Solve 15/18 + 1 21/42 as a fraction

Add 15/18 and 63/42

1^st number: 15/18, 2^nd number: 1 21/42

15/18 + 63/42 is 7/3.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 42 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126
Likewise, for the 2nd fraction, since 42 × 3 = 126,
63/42 = 63 × 3/42 × 3 = 189/126
Add the two like fractions:
105/126 + 189/126 = 105 + 189/126 = 294/126
294/126 simplified gives 7/3
So, 15/18 + 63/42 = 7/3
In mixed form: 21/3

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