Subtract 72/42 from 27/80, Solve 27/80

Subtract 72/42 from 27/80

1^st number: 27/80, 2^nd number: 1 30/42

27/80 - 72/42 is -771/560.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 42 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 80 × 21 = 1680,
27/80 = 27 × 21/80 × 21 = 567/1680
Likewise, for the 2nd fraction, since 42 × 40 = 1680,
72/42 = 72 × 40/42 × 40 = 2880/1680
Subtract the two like fractions:
567/1680 - 2880/1680 = 567 - 2880/1680 = -2313/1680
After reducing the fraction, the answer is -771/560

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