Add 80/21 and 28/18, Solve 3 17/21 + 1 10/18 as a fraction

Add 80/21 and 28/18

1^st number: 3 17/21, 2^nd number: 1 10/18

80/21 + 28/18 is 338/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 21 × 6 = 126,
80/21 = 80 × 6/21 × 6 = 480/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
28/18 = 28 × 7/18 × 7 = 196/126
Add the two like fractions:
480/126 + 196/126 = 480 + 196/126 = 676/126
676/126 simplified gives 338/63
So, 80/21 + 28/18 = 338/63
In mixed form: 523/63

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