Answer
To the left of the charges, there is a point where the net electric field is zero.
Work Step by Step
We can find write the general equation for the magnitude of an electric field:
$E = \frac{\vert q \vert}{4\pi ~\epsilon_0~r^2}$
Note that an electric field points toward a negative charge and away from a positive charge.
If we consider a point to the left of the $+q$ charge, the electric field due to the $+q$ charge will point to the left while the electric field due to the $-3q$ charge will point to the right. Although the magnitude of the $-3q$ charge is greater than the magnitude of the $+q$ charge, if the point on the axis is closer to the $+q$ charge, it is possible that the magnitudes of the electric fields could be equal.
To the left of the charges, there is a point where the net electric field is zero.
