Question

find the pair of integers whose sum is - 9

Answer 1

there are many pairs like:
-4,-5
-3,-6
and so on..

Answer 2

1 + ( -10 ) = -9

2 + ( - 11 ) = -9

3 + ( -12 ) = -9

4 + ( -13 ) = -9

5 + ( -14 ) = -9

etc

Hence there will be infinite number of pair whose sum is -9 .