Add 90/21 and 81/4, Solve 4 6/21 + 20 1/4 as a fraction

Add 90/21 and 81/4

1^st number: 4 6/21, 2^nd number: 20 1/4

90/21 + 81/4 is 687/28.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 4 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 21 × 4 = 84,
90/21 = 90 × 4/21 × 4 = 360/84
Likewise, for the 2nd fraction, since 4 × 21 = 84,
81/4 = 81 × 21/4 × 21 = 1701/84
Add the two like fractions:
360/84 + 1701/84 = 360 + 1701/84 = 2061/84
2061/84 simplified gives 687/28
So, 90/21 + 81/4 = 687/28
In mixed form: 2415/28

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