Add 36/21 and 90/81, Solve 1 15/21 + 1 9/81 as a fraction

Add 36/21 and 90/81

1^st number: 1 15/21, 2^nd number: 1 9/81

36/21 + 90/81 is 178/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 81 is 567

Next, find the equivalent fraction of both fractional numbers with denominator 567
For the 1st fraction, since 21 × 27 = 567,
36/21 = 36 × 27/21 × 27 = 972/567
Likewise, for the 2nd fraction, since 81 × 7 = 567,
90/81 = 90 × 7/81 × 7 = 630/567
Add the two like fractions:
972/567 + 630/567 = 972 + 630/567 = 1602/567
1602/567 simplified gives 178/63
So, 36/21 + 90/81 = 178/63
In mixed form: 252/63

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