Final answer:
The y-intercept of the graph of the equation y = 6 (x - 1) (x + 3) is -18.
Step-by-step explanation:
The y-intercept of the graph of the equation y = 6 (x - 1) (x + 3) can be found by setting x = 0 and solving for y.
When x = 0, the equation becomes y = 6 (0 - 1) (0 + 3).
Simplifying this expression, we get y = 6(-1)(3), which equals y = -18.
Therefore, the y-intercept of the graph is -18.