N-8 or 8-n I would assume
Answer:
(6,-2.5)
Step-by-step explanation:
The formula for the midpoint between two points is:

Now we substitute
We have than (9, -1) is
and (3, - 4) is 
So:

So, we have:

<h2>(6,-2.5)</h2><h2 />
I can do a graphic explanation if you want.
10 + 2p
increases by means addition
product means multiplication