Is this graph a function?

Is the following diagram a representation of a function?

Why or why not?
Is the following relationship a function?

Why or why not?
Does the set of ordered pairs represent a function?
(12, –18), (15, 1), (12, 5), (0, 9), (–5, –17)
Why or why not?
What is the slope of this line?

What is the slope of this line?

What is the initial value (y-intercept)?

What is the initial value (y-intercept)?

Is this graph a linear or nonlinear function?

Is this graph a linear or nonlinear function?

Is this graph a linear or nonlinear function?

Is this graph a linear or nonlinear function?
