Subtract 30/21 from 1/5, Solve 1/5 - 1 9/21 as a fraction

Subtract 30/21 from 1/5

1^st number: 1/5, 2^nd number: 1 9/21

1/5 - 30/21 is -43/35.

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,
1/5 = 1 × 21/5 × 21 = 21/105
Likewise, for the 2nd fraction, since 21 × 5 = 105,
30/21 = 30 × 5/21 × 5 = 150/105
Subtract the two like fractions:
21/105 - 150/105 = 21 - 150/105 = -129/105
After reducing the fraction, the answer is -43/35

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