Answer:
The particle P moves directly upwards
Explanation:
Lets designate the negative point charge at point P as particle P
The +Q charge will exert an attractive force on the particle P.
The -Q charge will exert a repulsive force on the particle P
The +Q charge exerts an upwards and leftward force on particle P
The -Q charge exerts an upwards and rightward force on particle P
Since the charges are equidistant from the particle P, and are of equal magnitude, the rightward force and the leftward force will cancel out, leaving just the upward force on the particle P.
The effect of the upward force is that the particle P moves directly upwards
