Add 63/42 and 90/20, Solve 1 21/42 + 4 10/20 as a fraction

Add 63/42 and 90/20

1^st number: 1 21/42, 2^nd number: 4 10/20

63/42 + 90/20 is 6/1.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 42 × 10 = 420,
63/42 = 63 × 10/42 × 10 = 630/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
90/20 = 90 × 21/20 × 21 = 1890/420
Add the two like fractions:
630/420 + 1890/420 = 630 + 1890/420 = 2520/420
2520/420 simplified gives 6/1
So, 63/42 + 90/20 = 6/1

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