when is the sum of a positive and a negative number equal to a negative number explain in at least one complete sentence then give an example for this

The sum of a positive and a negative number is negative when the negative number is further from 0 than the positive number.

Formally, we'd say that the negative number has to have a bigger absolute value than the positive number.

For instance, in the expression 3 + (-5), 3 is 3 units from 0, while - 5 is 5 units away - mathematically, |3| = 3 and |-5| = 5, so |-5| > |3|. Doing the addition and finding 3 + (-5) = - 2, a negative number, we find that this agrees with our initial definition.