Subtract 20/21 from 30/8, Solve 3 6/8

Subtract 20/21 from 30/8

1^st number: 3 6/8, 2^nd number: 20/21

30/8 - 20/21 is 235/84.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 8 × 21 = 168,
30/8 = 30 × 21/8 × 21 = 630/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
20/21 = 20 × 8/21 × 8 = 160/168
Subtract the two like fractions:
630/168 - 160/168 = 630 - 160/168 = 470/168
After reducing the fraction, the answer is 235/84
In mixed form: 267/84

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