Add 30/40 and 70/21, Solve 30/40 + 3 7/21 as a fraction

Add 30/40 and 70/21

1^st number: 30/40, 2^nd number: 3 7/21

30/40 + 70/21 is 49/12.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 40 × 21 = 840,
30/40 = 30 × 21/40 × 21 = 630/840
Likewise, for the 2nd fraction, since 21 × 40 = 840,
70/21 = 70 × 40/21 × 40 = 2800/840
Add the two like fractions:
630/840 + 2800/840 = 630 + 2800/840 = 3430/840
3430/840 simplified gives 49/12
So, 30/40 + 70/21 = 49/12
In mixed form: 41/12

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