PSAT Math Multiple-Choice Question 547: Answer and Explanation

Question: 547

The xy-plane above shows line f. For constants r and s, the equation y = rx + s represents line f. Which of the following sets of inequalities is true about r and s?

• A.
• B.
• C.
• D.

Correct Answer: D

Explanation:

D

The question asks for a set of inequalities that are true for the slope and the y-intercept of a line on a graph. To find the correct set of inequalities, compare features of the graph to the answer choices. The equation is given in slope-intercept form, so r is the slope of the line and s is the y-intercept. The graph for this question has a y-intercept of 3 and a negative slope. Eliminate answer choices that do not match this information. Choices (A) and (B) say r, the slope, is positive. Eliminate (A) and (B), since they are not consistent with the graph's negative slope. Choice (C) says s, the y-intercept, is less than 1. Eliminate (C) since this is not consistent with the graph's y-intercept of 3. The correct answer is (D).