Subtract 84/36 from 4/21, Solve 4/21

Subtract 84/36 from 4/21

1^st number: 4/21, 2^nd number: 2 12/36

4/21 - 84/36 is -15/7.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 36 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 21 × 12 = 252,
4/21 = 4 × 12/21 × 12 = 48/252
Likewise, for the 2nd fraction, since 36 × 7 = 252,
84/36 = 84 × 7/36 × 7 = 588/252
Subtract the two like fractions:
48/252 - 588/252 = 48 - 588/252 = -540/252
After reducing the fraction, the answer is -15/7

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