What's the point here? Why would you remove one of the ordered pairs?
The only thing I see here that hints at an answer is that -1 is the first term of both (-1,1) and -1,0). If we got rid of one of these, then the relationship could be a function; otherwise it is not a function. Why? Because in the case of a function, all first elements of the ordered pairs are unique (different from all the other first elements).
