Answer:
It is very difficult to know because you did not include the function g(x), you only gave us f(x).
Given two lists of ordered pairs [x,f(x)] and [x,g(x)]. If for every ordered pair on the f(x) list the reverse is on the g(x) list the functions are inverses.
f(0) = 5 so for (0,5) on the f(x) list then (5,0) must be on the g(x) list
f(1) = 7 so for (1,7) on the f(x) list then (7,1) must be on the g(x) list
f(2) = 9 so for (2,9) on the f(x) list then (9,2) must be on the g(x) list
So even though you didn’t list g(x), g(x) = (x/2) - 5/2