Explain the different ways it is possible to add two rational numbers and get a negative number

both numbers are negative
negative number is greater than the positive number

Explanation:
In order to add two rational numbers and get a negative value, one of two scenarios should occur:
1- both numbers are negative.
In this case, the answer would definitely be negative as the two numbers are originally negative
Examples:
-9 + -2 = -9 - 2 = -11


2- negative number is greater than the positive number
In this case, the negative sign would dominate and the result would be negative
Examples:
-9 + 3 = -6


Hope this helps :)

-- If both of them are negative,

or

-- If their signs are different and the negative number has
a bigger absolute value than the positive one,

then

-- Their sum is negative.

Actually, I don't think it matters whether they're rational or not.