PSAT Math Multiple-Choice Question 27: Answer and Explanation

Question: 27

What is the x-intercept of the line in the graph above?

• A. -1
• B. 0
• C. 1
• D. 2

Correct Answer: D

Explanation:

D

The question asks for the x-intercept of the line shown in the graph. The x-intercept of a line is the point where the line crosses the x-axis. The line in the graph has a positive x-intercept, so eliminate (A) and (B). To find the x-intercept, first find the slope of the line and then use one of the points given to determine the value of x. The slope of a line is determined by the equation . The slope of the line shown is . Continue to simplify the expression to find a slope of . At the x-intercept, y =0, so the coordinates for the x-intercept are (x, 0). To find x, plug points (x, 0) and (-2, -2) into the slope equation and solve for x: . Cross-multiply to get -2 - x = -4, or -x = -2. Therefore, x = 2. The correct answer is (D).