We Need To Remember Order of Operations.
So, We Do:
4+5.
We Know That 4 + 5 = 9, So We Have:
9 <span>÷ 3 * 4
Now, We Do:
9 </span><span>÷ 3
This Is 3, So We Have:
3 * 4.
We Know That 3 * 4 Is 12, So:
We Know That The Answer To This Expression Is 12.</span>
Answer:

Step-by-step explanation:
Let points D, E and F have coordinates
and 
1. Midpoint M of segment DF has coordinates

2. Midpoint N of segment EF has coordinates

3. By the triangle midline theorem, midline MN is parallel to the side DE of the triangle DEF, then points M and N are endpoints of the midsegment for DEF that is parallel to DE.
The answer is B :)
Hope this helped :)