Answer
(a) $1.50m$
(b) $-1.50m$
Work Step by Step
(a) We know that
$V_A=K(\frac{q}{0.5}-\frac{2q}{x-0.5})$
$\implies \frac{q}{0.5}-\frac{2q}{x-0.5}=0$
$\implies \frac{1}{0.5}=\frac{2}{x-0.5}$
This simplifies to:
$x=1.5m$
(b) As $V_B=K(\frac{q}{-x}-\frac{2q}{1.5-x})=0$
$\implies -\frac{q}{x}=\frac{2q}{1.5-x}$
$\implies -\frac{1}{x}=\frac{2}{1.5-x}$
This simplifies to:
$x=-1.5m$
