Add 70/21 and 21/90, Solve 3 7/21 + 21/90 as a fraction

Add 70/21 and 21/90

1^st number: 3 7/21, 2^nd number: 21/90

70/21 + 21/90 is 107/30.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 21 × 30 = 630,
70/21 = 70 × 30/21 × 30 = 2100/630
Likewise, for the 2nd fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630
Add the two like fractions:
2100/630 + 147/630 = 2100 + 147/630 = 2247/630
2247/630 simplified gives 107/30
So, 70/21 + 21/90 = 107/30
In mixed form: 317/30

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