Add 90/21 and 21/80, Solve 4 6/21 + 21/80 as a fraction

Add 90/21 and 21/80

1^st number: 4 6/21, 2^nd number: 21/80

90/21 + 21/80 is 2547/560.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
90/21 = 90 × 80/21 × 80 = 7200/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
21/80 = 21 × 21/80 × 21 = 441/1680
Add the two like fractions:
7200/1680 + 441/1680 = 7200 + 441/1680 = 7641/1680
7641/1680 simplified gives 2547/560
So, 90/21 + 21/80 = 2547/560
In mixed form: 4307/560

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