Add 64/21 and 28/40, Solve 3 1/21 + 28/40 as a fraction

Add 64/21 and 28/40

1^st number: 3 1/21, 2^nd number: 28/40

64/21 + 28/40 is 787/210.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 21 × 40 = 840,
64/21 = 64 × 40/21 × 40 = 2560/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
28/40 = 28 × 21/40 × 21 = 588/840
Add the two like fractions:
2560/840 + 588/840 = 2560 + 588/840 = 3148/840
3148/840 simplified gives 787/210
So, 64/21 + 28/40 = 787/210
In mixed form: 3157/210

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