Add 84/21 and 70/9, Solve 4 0/21 + 7 7/9 as a fraction

Add 84/21 and 70/9

1^st number: 4 0/21, 2^nd number: 7 7/9

84/21 + 70/9 is 106/9.

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,
84/21 = 84 × 3/21 × 3 = 252/63
Likewise, for the 2nd fraction, since 9 × 7 = 63,
70/9 = 70 × 7/9 × 7 = 490/63
Add the two like fractions:
252/63 + 490/63 = 252 + 490/63 = 742/63
742/63 simplified gives 106/9
So, 84/21 + 70/9 = 106/9
In mixed form: 117/9

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