Subtract 54/42 from 54/80, Solve 54/80

Subtract 54/42 from 54/80

1^st number: 54/80, 2^nd number: 1 12/42

54/80 - 54/42 is -171/280.

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,
54/80 = 54 × 21/80 × 21 = 1134/1680
Likewise, for the 2nd fraction, since 42 × 40 = 1680,
54/42 = 54 × 40/42 × 40 = 2160/1680
Subtract the two like fractions:
1134/1680 - 2160/1680 = 1134 - 2160/1680 = -1026/1680
After reducing the fraction, the answer is -171/280

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