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!! (:

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle