Suppose the graph of y = f(x) includes the points (1,-5), (2,3) and (3,-1). Based only on this information, there are two points that must be on the graph of y = f(f(x)) . If we call those points (a,b) and (c,d) what is ab + cd?

Reflect points, 2,3 and 3,-1 over 1,-5. so the other two points are 0,3 and -1,-1 so the answer would be 0+1 so 1