Subtract 16/18 from 9/21, Solve 9/21

Subtract 16/18 from 9/21

9/21 - 16/18 is -29/63.

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,
9/21 = 9 × 6/21 × 6 = 54/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
16/18 = 16 × 7/18 × 7 = 112/126
Subtract the two like fractions:
54/126 - 112/126 = 54 - 112/126 = -58/126
After reducing the fraction, the answer is -29/63

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