Subtract 90/80 from 10/84, Solve 10/84

Subtract 90/80 from 10/84

1^st number: 10/84, 2^nd number: 1 10/80

10/84 - 90/80 is -169/168.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 84 × 20 = 1680,
10/84 = 10 × 20/84 × 20 = 200/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
90/80 = 90 × 21/80 × 21 = 1890/1680
Subtract the two like fractions:
200/1680 - 1890/1680 = 200 - 1890/1680 = -1690/1680
After reducing the fraction, the answer is -169/168

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