Recall that a (unital) ring $R$ is von Neumann regular (VNR) if, for each $x \in R$, there exists $y \in R$ such that $x = xyx$; and unit-regular if such an element $y$ can be taken to be a unit.
Question. Assume $R$ is a VNR (resp., unit-regular) ring, and let $a, b \in R$ be such that the right annihilator $r(a)$ of $a$ equals to the right annihilator $r(b)$ of $b$. Does it follow that $aR = bR$?
It is relatively simple to see that, if $R$ is a VNR ring and $r(a) = r(b)$ for some $a, b \in R$, then $Ra = Rb$: This is true, more generally, for a right principally injective ring (see, e.g., Lemma 5.1 in Nicholson and Yousif's book on quasi-Frobenius rings); and it is a matter of fact that VNR rings are (left and) right principally injective.