Easy# Potential of Two Identical Charges on a Line at the Origin

EANDM-$EG@98

Figure 1 depicts a pair of negatively charged particles, each having a charge of $-q$, arrayed along the $\hat{x}$ axis, symmetrically about the origin.

What is the electric potential $V$ at the origin of the $\hat{x}$ axis? Take $k = 8.99 \times 10^9 \text{ N} \cdot \text{ m}^2 / \text{C}^2$ as the electric force constant.