Answer:
It is -
throughout the line
Explanation:
The points O, A and B lie on the line and so the slope will be the same for OA, OB and AB
Calculate the slope m using the slope formula
m =

with (x₁, y₁ ) = B(- 12, 3) and (x₂, y₂ ) = O(0, 0)
m =
=
= -

Thus the slope is -
throughout the line.