Subtract 84/18 from 16/21, Solve 16/21

Subtract 84/18 from 16/21

1^st number: 16/21, 2^nd number: 4 12/18

16/21 - 84/18 is -82/21.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 21 × 6 = 126,
16/21 = 16 × 6/21 × 6 = 96/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
84/18 = 84 × 7/18 × 7 = 588/126
Subtract the two like fractions:
96/126 - 588/126 = 96 - 588/126 = -492/126
After reducing the fraction, the answer is -82/21

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