Add 70/42 and 72/20, Solve 1 28/42 + 3 12/20 as a fraction

Add 70/42 and 72/20

1^st number: 1 28/42, 2^nd number: 3 12/20

70/42 + 72/20 is 79/15.

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,
70/42 = 70 × 10/42 × 10 = 700/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420
Add the two like fractions:
700/420 + 1512/420 = 700 + 1512/420 = 2212/420
2212/420 simplified gives 79/15
So, 70/42 + 72/20 = 79/15
In mixed form: 54/15

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