Subtract 7/21 from 9/80, Solve 9/80

Subtract 7/21 from 9/80

9/80 - 7/21 is -53/240.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 80 × 21 = 1680,
9/80 = 9 × 21/80 × 21 = 189/1680
Likewise, for the 2nd fraction, since 21 × 80 = 1680,
7/21 = 7 × 80/21 × 80 = 560/1680
Subtract the two like fractions:
189/1680 - 560/1680 = 189 - 560/1680 = -371/1680
After reducing the fraction, the answer is -53/240

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