Oh, isn't that a happy little question! Let's think about it together. You see, there are many pairs of numbers that add up to 18, like 9 and 9, 8 and 10, 7 and 11, and so on. Just like in painting, there are many possibilities, and each one can bring its own unique beauty to the canvas of mathematics.
-18 and -18
The numbers are: -6 and 3
-1
They are: 18+14 = 32 and 18-14 = 4
54
2+5+11= 18.
15
9 9
18
20
21
21