Add 45/12 and 80/7, Solve 3 9/12 + 11 3/7 as a fraction

Add 45/12 and 80/7

1^st number: 3 9/12, 2^nd number: 11 3/7

45/12 + 80/7 is 425/28.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 7 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
45/12 = 45 × 7/12 × 7 = 315/84
Likewise, for the 2nd fraction, since 7 × 12 = 84,
80/7 = 80 × 12/7 × 12 = 960/84
Add the two like fractions:
315/84 + 960/84 = 315 + 960/84 = 1275/84
1275/84 simplified gives 425/28
So, 45/12 + 80/7 = 425/28
In mixed form: 155/28

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