Add 21/12 and 54/21, Solve 1 9/12 + 2 12/21 as a fraction

Add 21/12 and 54/21

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

21/12 + 54/21 is 121/28.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
21/12 = 21 × 7/12 × 7 = 147/84
Likewise, for the 2nd fraction, since 21 × 4 = 84,
54/21 = 54 × 4/21 × 4 = 216/84
Add the two like fractions:
147/84 + 216/84 = 147 + 216/84 = 363/84
363/84 simplified gives 121/28
So, 21/12 + 54/21 = 121/28
In mixed form: 49/28

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