Subtract 90/63 from 12/18, Solve 12/18

Subtract 90/63 from 12/18

1^st number: 12/18, 2^nd number: 1 27/63

12/18 - 90/63 is -16/21.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 63 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 18 × 7 = 126,
12/18 = 12 × 7/18 × 7 = 84/126
Likewise, for the 2nd fraction, since 63 × 2 = 126,
90/63 = 90 × 2/63 × 2 = 180/126
Subtract the two like fractions:
84/126 - 180/126 = 84 - 180/126 = -96/126
After reducing the fraction, the answer is -16/21

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