84 the process is shown in the following picture
9+10 = 21 you stupid you stupid no I’m not
The graph of the relation between x and y is as shown in attached figure
By applying the vertical line test we find that the relation is not a function because there are two points which are (1,-1) , (1,3) have the same value of x with different values of y which contradicts with with the rule of function.
I think the answer is A but I am not sure. I think you would take the opposite of the y axis.