Final answer:
To find f(-4), substitute -4 into the function f and obtain the corresponding output.
Step-by-step explanation:
To find f(-4), we need to look at the given function f and determine the corresponding value for the input -4.
The function f is defined as {(8,9),(2,-4),(-4,-5)}. This means that when the input is 8, the output is 9, when the input is 2, the output is -4, and when the input is -4, the output is -5.
Therefore, f(-4) = -5.