This table represent a function ? ... What is f(-2)?

Answer:
Yeah, it tells you values from when x and y are both -2, so I don't know why you need us to tell you.
Step-by-step explanation:
If you meant to ask something else, the way to find an X value is
Y = -0.5555555555555556 X — 0.3333333333333335
Just plug in x, and you'll get Y.