What is the blank?
Blank+(-6)+(-3)=-17

The blank is -8 because -6 +-8=-14+-3=-17.

The answer to this problem would be -8.

__ + (-6) + (-3) = -17

Since the parentheses are only there to differentiate the pluses from the negative signs, we can add together -6 and -3, which equals -9.
Now we have __ + (-9) = -17

We want to get the blank on its own side. To do this, you do the opposite of whatever's on the other side. Since it's a negative nine, you have to add a positive nine to the negative seventeen.

So, we have = -17 + 9

-17 + 9 = -8

Hope this helped, and feel free to ask more questions!! (: