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

Subtract 21/5 from 3/21

1^st number: 3/21, 2^nd number: 4 1/5

3/21 - 21/5 is -142/35.

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

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 21 × 5 = 105,
3/21 = 3 × 5/21 × 5 = 15/105
Likewise, for the 2nd fraction, since 5 × 21 = 105,
21/5 = 21 × 21/5 × 21 = 441/105
Subtract the two like fractions:
15/105 - 441/105 = 15 - 441/105 = -426/105
After reducing the fraction, the answer is -142/35

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