With this in mind,
x + y = -3
x * y = -18
Then we will think about which ones could add up to 3
1 & 18, 2 & 9, 3 & 6 are factors of 18 (one being negative results in -18)
Well 1 and 18 cannot make 3, same for 2 and 9, that leaves us with 3 and 6.
You can see our test shows this solution works!
-6 + 3 = -3
-6 * 3 = -18
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather