Explain how you can determine the sign of the sum of two integers if one integer is positive and the other integer is negative.

To add integers with different signs, keep the sign of the number with the largest absolute value and subtract the smallest absolute value from the largest.

So, here's an example.
Lets say you have this problem:
-4+5
The answer would be 1 because when you add integers with different signs, you keep the sign of the number with the largest absolute value and subtract the smallest absolute value from the largest.
Here's another:
7-2
The answer would be 5 because you keep the sign of the number with the largest absolute value and subtract the smaller absolute value from it.

use the number line.

plot one of the numbers.
Move left to add a negative number, move right to add a positive number.
you'll soon see that the sign of the larger value prevails.