Add 21/4 and 12/72, Solve 5 1/4 + 12/72 as a fraction

Add 21/4 and 12/72

1^st number: 5 1/4, 2^nd number: 12/72

21/4 + 12/72 is 65/12.

Find the least common denominator or LCM of the two denominators:
LCM of 4 and 72 is 72

Next, find the equivalent fraction of both fractional numbers with denominator 72
For the 1st fraction, since 4 × 18 = 72,
21/4 = 21 × 18/4 × 18 = 378/72
Likewise, for the 2nd fraction, since 72 × 1 = 72,
12/72 = 12 × 1/72 × 1 = 12/72
Add the two like fractions:
378/72 + 12/72 = 378 + 12/72 = 390/72
390/72 simplified gives 65/12
So, 21/4 + 12/72 = 65/12
In mixed form: 55/12

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