Subtract 70/21 from 18/5, Solve 3 3/5

Subtract 70/21 from 18/5

1^st number: 3 3/5, 2^nd number: 3 7/21

18/5 - 70/21 is 4/15.

Find the least common denominator or LCM of the two denominators:
LCM of 5 and 21 is 105

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 5 × 21 = 105,
18/5 = 18 × 21/5 × 21 = 378/105
Likewise, for the 2nd fraction, since 21 × 5 = 105,
70/21 = 70 × 5/21 × 5 = 350/105
Subtract the two like fractions:
378/105 - 350/105 = 378 - 350/105 = 28/105
After reducing the fraction, the answer is 4/15

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