What is the slope of the line that contains the points (1, −9) and (−3, 3)?

a) 3
b) −3
c) one third
d) negative one third

To find the slope of the line that contains the points (1, −9) and (−3, 3), we can use the formula for slope:

slope = (y₂ - y₁) / (x₂ - x₁)

Plugging in the points (1, −9) for (x₁, y₁) and (−3, 3) for (x₂, y₂), we get:

slope = (3 - (-9)) / (−3 - 1)
slope = 12 / -4
slope = -3

Therefore, the slope of the line that contains the points (1, −9) and (−3, 3) is -3.

Option b) is correct: -3.