Subtract 16/18 from 21/28, Solve 21/28

Subtract 16/18 from 21/28

21/28 - 16/18 is -5/36.

Find the least common denominator or LCM of the two denominators:
LCM of 28 and 18 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 28 × 9 = 252,
21/28 = 21 × 9/28 × 9 = 189/252
Likewise, for the 2nd fraction, since 18 × 14 = 252,
16/18 = 16 × 14/18 × 14 = 224/252
Subtract the two like fractions:
189/252 - 224/252 = 189 - 224/252 = -35/252
After reducing the fraction, the answer is -5/36

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