SAT Math Multiple Choice Question 369: Answer and Explanation
9. If a line that passes through the coordinates (a - 1, 2a) and (a, 6) has a slope of 5, what is the value of a?
- A. -2
- D. 2
Correct Answer: C
Category: Heart of Algebra / Linear Equations
Strategic Advice: Given two points (even when the coordinates are variables), the slope of the line is
Getting to the Answer: You are given a numerical value for the slope and a pair of coordinate points with variables. To find the value of a, plug the points into the slope formula, and then solve for a.