Add 72/21 and 3/12, Solve 3 9/21 + 3/12 as a fraction

Add 72/21 and 3/12

1^st number: 3 9/21, 2^nd number: 3/12

72/21 + 3/12 is 103/28.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 21 × 4 = 84,
72/21 = 72 × 4/21 × 4 = 288/84
Likewise, for the 2nd fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84
Add the two like fractions:
288/84 + 21/84 = 288 + 21/84 = 309/84
309/84 simplified gives 103/28
So, 72/21 + 3/12 = 103/28
In mixed form: 319/28

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