Answer
THe answer is -11.
Work Step by Step
-6 + (-5) = -11
Since both numbers are negative, we can just add the numbers 6 and 5. 6 + 5 = 11. Now, we noted that both were negative, this means that our answer must also be negative, so -6 + (-5) = -11.
Note: The parentheses around the (-5) is to keep us from "losing" the sign when we copy the problem. If it weren't there, the problem would look messy and we could easily fail to see one of the signs when we work the problem. Example: -6 + (-5) looks much clearer than -6 + -5