Add 81/12 and 21/40, Solve 6 9/12 + 21/40 as a fraction

Add 81/12 and 21/40

1^st number: 6 9/12, 2^nd number: 21/40

81/12 + 21/40 is 291/40.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 40 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 12 × 10 = 120,
81/12 = 81 × 10/12 × 10 = 810/120
Likewise, for the 2nd fraction, since 40 × 3 = 120,
21/40 = 21 × 3/40 × 3 = 63/120
Add the two like fractions:
810/120 + 63/120 = 810 + 63/120 = 873/120
873/120 simplified gives 291/40
So, 81/12 + 21/40 = 291/40
In mixed form: 711/40

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