Answer:
11.6km 
4.4km in the negative direction
Step-by-step explanation:
Distance is the total length of path covered and traveled by a body. 
 So, for this car on a straight line; 
 Total distance = 8km + 3.6km = 11.6km 
Displacement is the distance traveled along a path and the direction it takes. 
It is a vector quantity with magnitude and directional attributes. 
 For this journey; 
 Displacement = 8km - 3.6km = 4.4km in the negative direction.