Difference between revisions of "2023 AMC 12B Problems/Problem 14"
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+ | ==Solution== | ||
+ | Denote three roots as <math>r_1 < r_2 < r_3</math>. | ||
+ | Following from Vieta's formula, <math>r_1r_2r_3 = -6</math>. | ||
+ | |||
+ | Case 1: All roots are negative. | ||
+ | |||
+ | We have the following solution: <math>\left( -3, -2, -1 \right)</math>. | ||
+ | |||
+ | Case 2: One root is negative and two roots are positive. | ||
+ | |||
+ | We have the following solutions: <math>\left( -3, 1, 2 \right)</math>, <math>\left( -2, 1, 3 \right)</math>, <math>\left( -1, 2, 3 \right)</math>, <math>\left( -1, 1, 6 \right)</math>. | ||
+ | |||
+ | Putting all cases together, the total number of solutions is | ||
+ | \boxed{\textbf{(A) 5}}. | ||
+ | |||
+ | ~Steven Chen (Professor Chen Education Palace, www.professorchenedu.com) |
Revision as of 17:31, 15 November 2023
Solution
Denote three roots as . Following from Vieta's formula, .
Case 1: All roots are negative.
We have the following solution: .
Case 2: One root is negative and two roots are positive.
We have the following solutions: , , , .
Putting all cases together, the total number of solutions is \boxed{\textbf{(A) 5}}.
~Steven Chen (Professor Chen Education Palace, www.professorchenedu.com)