Add 72/21 and 18/5, Solve 3 9/21 + 3 3/5 as a fraction

Add 72/21 and 18/5

1^st number: 3 9/21, 2^nd number: 3 3/5

72/21 + 18/5 is 246/35.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 21 × 5 = 105,
72/21 = 72 × 5/21 × 5 = 360/105
Likewise, for the 2nd fraction, since 5 × 21 = 105,
18/5 = 18 × 21/5 × 21 = 378/105
Add the two like fractions:
360/105 + 378/105 = 360 + 378/105 = 738/105
738/105 simplified gives 246/35
So, 72/21 + 18/5 = 246/35
In mixed form: 71/35

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