OG详解-OG6 数学2 Q12

Choice C is correct. Applying the zero product property to the given equation yields three equations: ×+2 = 0, ×-5 = 0, and ×+9 = 0. Subtracting 2 from both sides of the equation ×+2 = 0 yields × =-2. Adding 5 to both sides of the equation ×-5 = 0 yields × = 5. Subtracting 9 from both sides of the equation ×+9 = 0 yields × =-9. Therefore, the solutions to the given equation are -2, 5, and -9. It follows that a positive solution to the given equation is 5.
Choice A is incorrect and may result from conceptual or calculation errors. Choice B is incorrect and may result from conceptual or calculation errors. Choice D is incorrect and may result from conceptual or calculation errors.