What two numbers added together make minus 8?

Answer 1

There are infinitely many possible answers.

Two ways to look at that:

Pick any number - integer, rational, irrational : positive or negative. You can even pick a complex number, if you know what that is. Call this number x.

Let y = negative x minus 8 = -x - 8

Then x + y = x + (-x - 8) = x - x - 8 = -8

Since x was any one of infinitely many numbers there are infinitely many pairs of number that sum to -8.

ALTERNATIVELY

Consider

(1, - 9), (2, -10), (3, -11), ...

Then add 0.1 to all numbers

(1.1, -9.1), (2.1, -10.1),

and then 0.2, and 0.3, 0.4 etc.

Then go for two decimal places, 3 dp, 4 dp, ...

There can be infinitely many decimal places.

So again, you have infinitely many pairs.