Add 28/21 and 35/12, Solve 1 7/21 + 2 11/12 as a fraction

Add 28/21 and 35/12

1^st number: 1 7/21, 2^nd number: 2 11/12

28/21 + 35/12 is 17/4.

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,
28/21 = 28 × 4/21 × 4 = 112/84
Likewise, for the 2nd fraction, since 12 × 7 = 84,
35/12 = 35 × 7/12 × 7 = 245/84
Add the two like fractions:
112/84 + 245/84 = 112 + 245/84 = 357/84
357/84 simplified gives 17/4
So, 28/21 + 35/12 = 17/4
In mixed form: 41/4

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