Add 20/21 and 30/9, Solve 20/21 + 3 3/9 as a fraction

Add 20/21 and 30/9

1^st number: 20/21, 2^nd number: 3 3/9

20/21 + 30/9 is 30/7.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63

Next, find the equivalent fraction of both fractional numbers with denominator 63
For the 1st fraction, since 21 × 3 = 63,
20/21 = 20 × 3/21 × 3 = 60/63
Likewise, for the 2nd fraction, since 9 × 7 = 63,
30/9 = 30 × 7/9 × 7 = 210/63
Add the two like fractions:
60/63 + 210/63 = 60 + 210/63 = 270/63
270/63 simplified gives 30/7
So, 20/21 + 30/9 = 30/7
In mixed form: 42/7

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