Add 80/20 and 81/21, Solve 4 0/20 + 3 18/21 as a fraction

Add 80/20 and 81/21

1^st number: 4 0/20, 2^nd number: 3 18/21

80/20 + 81/21 is 55/7.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 20 × 21 = 420,
80/20 = 80 × 21/20 × 21 = 1680/420
Likewise, for the 2nd fraction, since 21 × 20 = 420,
81/21 = 81 × 20/21 × 20 = 1620/420
Add the two like fractions:
1680/420 + 1620/420 = 1680 + 1620/420 = 3300/420
3300/420 simplified gives 55/7
So, 80/20 + 81/21 = 55/7
In mixed form: 76/7

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