Answer:
directed to the left
Explanation:
You are trying to find the position on the x-axis of charge 3. Assuming that the load 1 is at the origin of the x-axis and the positive x-axis points to the right.
There are two possible configurations with two values for x3:
- a positive value x3 when charge 3 is to the right of charge 1 and between the two charges
- a negative value x3 when charge 3 is found to the left of charge 1 (that is, to the left of the origin).
Therefore, if the charge 3 is somewhere to the left of the charge 1, both electric forces exerted on it point to the left.
Then the net force on the charge 3 will also be directed to the left.
Hope this helps!