Add 28/21 and 63/54, Solve 1 7/21 + 1 9/54 as a fraction

Add 28/21 and 63/54

1^st number: 1 7/21, 2^nd number: 1 9/54

28/21 + 63/54 is 5/2.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 21 × 18 = 378,
28/21 = 28 × 18/21 × 18 = 504/378
Likewise, for the 2nd fraction, since 54 × 7 = 378,
63/54 = 63 × 7/54 × 7 = 441/378
Add the two like fractions:
504/378 + 441/378 = 504 + 441/378 = 945/378
945/378 simplified gives 5/2
So, 28/21 + 63/54 = 5/2
In mixed form: 21/2

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