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

Subtract 16/18 from 21/84

21/84 - 16/18 is -23/36.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 18 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 84 × 3 = 252,
21/84 = 21 × 3/84 × 3 = 63/252
Likewise, for the 2nd fraction, since 18 × 14 = 252,
16/18 = 16 × 14/18 × 14 = 224/252
Subtract the two like fractions:
63/252 - 224/252 = 63 - 224/252 = -161/252
After reducing the fraction, the answer is -23/36

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