PSAT Math Multiple-Choice Question 726: Answer and Explanation

Question: 726

The variables x and y have a linear relationship; the table below contains several corresponding x-y values for the line. What is the equation of the line made up of x-y values?

x	y
-1	-6
1	2
5	18
7	26

• A. y = 4x - 2
• B. y = 2x
• C. y = -2x + 4
• D. y = -4x + 2

Correct Answer: A

Explanation:

(A) Take the slope of the line using relatively simple points from the table, like (1, 2) and (5, 18):

The only choice with a slope of 4 is (A).