Question 633754
Function is a set of ordered pairs where each first element is paired 
with one and only one second element and no element in either pair 
is without a partner. 

remember:

• a relation is a function if every input has exactly one output

      • in the plot, for each x-coordinate, there is only one y-coordinate
     
      • the domain is 1, 2, 3, 5 and 6 and the range is 2, 3, 4, 6 and 7. [The x-coordinates of the points are the domain and the y- coordinates are the range.]

you have

{(-2, -7), (3, -5), (6, -4), (9, -6), (10, -1)}

as you can see, for each x-coordinate, there is only one y-coordinate

your the domain is -2, 3, 6,9 and 10 and the range is -7, -5, -4, -6 and -1

so, the relation {{{is}}} {{{a}}} {{{function}}}