Digital PSAT Math Practice Question 312: Answer and Explanation

Question: 312

Which equation expresses the relationship between x and y shown in the graph above?

• A. $y=\frac{1}{2}x-3$
• B. $y=3x-3$
• C. $y=2x+6$
• D. $y=-\frac{2}{3}x+6$

Correct Answer: A

Explanation:

(A) This line has a y-intercept of -3 because that is where the line intersects the y-axis. You can calculate the slope using points on the line, $(0,-3)$ and $(6,0)$:

Putting this in slope-intercept form $(y=mx+b)$ results in the equation of the line: