Find a positive number which, when multiplied by 2 and decreased by 10, is equal to 12 times the reciprocal of the number.
Correct answer: C
Explanation
The condition gives 2x - 10 = 12/x, which becomes 2x^2 - 10x - 12 = 0, or x^2 - 5x - 6 = 0. Factoring as (x - 6)(x + 1) = 0 gives x = 6 or x = -1, and the positive value is 6.