Add 72/21 and 27/28, Solve 3 9/21 + 27/28 as a fraction

Add 72/21 and 27/28

1^st number: 3 9/21, 2^nd number: 27/28

72/21 + 27/28 is 123/28.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 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 28 × 3 = 84,
27/28 = 27 × 3/28 × 3 = 81/84
Add the two like fractions:
288/84 + 81/84 = 288 + 81/84 = 369/84
369/84 simplified gives 123/28
So, 72/21 + 27/28 = 123/28
In mixed form: 411/28

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