Final answer:
The slope between the points (4, -9) and (2, -1) is -4.
Step-by-step explanation:
To calculate the slope between two points, we use the formula: slope = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are the coordinates of the two points. In this case, the two points are (4, -9) and (2, -1). Plugging in the values, we get:
slope = (-1 - (-9)) / (2 - 4) = 8 / (-2) = -4
Therefore, the slope between the given points is -4. So, the correct answer is a. -4.