Add 30/54 and 72/21, Solve 30/54 + 3 9/21 as a fraction

Add 30/54 and 72/21

1^st number: 30/54, 2^nd number: 3 9/21

30/54 + 72/21 is 251/63.

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

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 54 × 7 = 378,
30/54 = 30 × 7/54 × 7 = 210/378
Likewise, for the 2nd fraction, since 21 × 18 = 378,
72/21 = 72 × 18/21 × 18 = 1296/378
Add the two like fractions:
210/378 + 1296/378 = 210 + 1296/378 = 1506/378
1506/378 simplified gives 251/63
So, 30/54 + 72/21 = 251/63
In mixed form: 362/63

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