I'm not exactly sure, so if I'm wrong please correct me.
The equation is 2kg + x = s
↓
(can be any variable letter)
Answer:
b. y = -9
Step-by-step explanation:
A line with zero slope has no dependence on x. It is simply ...
... y = constant
The constant must be the same as the y-value of the point you want the line to go through. Since the point is (12, -9), the constant is -9 and the equation is ...
... y = -9