Add 81/21 and 30/80, Solve 3 18/21 + 30/80 as a fraction

Add 81/21 and 30/80

1^st number: 3 18/21, 2^nd number: 30/80

81/21 + 30/80 is 237/56.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
81/21 = 81 × 80/21 × 80 = 6480/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
30/80 = 30 × 21/80 × 21 = 630/1680
Add the two like fractions:
6480/1680 + 630/1680 = 6480 + 630/1680 = 7110/1680
7110/1680 simplified gives 237/56
So, 81/21 + 30/80 = 237/56
In mixed form: 413/56

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