Add 21/70 and 70/18, Solve 21/70 + 3 16/18 as a fraction

Add 21/70 and 70/18

1^st number: 21/70, 2^nd number: 3 16/18

21/70 + 70/18 is 377/90.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 18 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 70 × 9 = 630,
21/70 = 21 × 9/70 × 9 = 189/630
Likewise, for the 2nd fraction, since 18 × 35 = 630,
70/18 = 70 × 35/18 × 35 = 2450/630
Add the two like fractions:
189/630 + 2450/630 = 189 + 2450/630 = 2639/630
2639/630 simplified gives 377/90
So, 21/70 + 70/18 = 377/90
In mixed form: 417/90

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