Answer
domain: $\{x|x\neq\frac{1}{2}\}$
Work Step by Step
We are given:
$f(x)= \frac{2x+1}{2x-1}$
We know that the denominator can not be zero:
$2x-1 \neq 0$
$x\neq\frac{1}{2}$
Thus the domain is all real numbers except for $\frac{1}{2}$: $\{x|x\neq\frac{1}{2}\}$.