Question

find two consecutive even integers whose sum is -9

Answer 1

the sum of two even integers will always be even, since -9 isnt an even number there are no such numbers

Answer 2

good catch @CalebBeavers . I didn't read the whole question.

n+(n+2)=-9
2n+2=-9
2n=-11
n=-5.5 not an integer. no answer

But Caleb's common sense answer works too