PSAT Math Multiple-Choice Question 183: Answer and Explanation

Question: 183

Which of the following could be the factored form of the equation graphed in the figure above?

• A.
• B.
• C.
• D.

Correct Answer: D

Explanation:

D

Difficulty: Easy

Category: Passport to Advanced Math/Quadratics

Getting to the Answer: A root of an equation is an x-value that corresponds to a y-value of 0. The x-intercepts of the graph, and therefore the roots of the equation, are x = - 1 and x = 5. When x = - 1, the value of x + 1 is 0, so one of the factors is x + 1. When x = 5, the value of x - 5 is 0, so the other factor is x - 5. The equation in (D) is the only one that contains these factors and is therefore correct.