Variable $x$ cannot be equal to $\frac{1}{2}$ since division by zero is not defined. Multiply both sides of the equation by $3\left(2x-1\right)$, the least common multiple of $2x-1,3$.
$$3\times 3=2\left(2x-1\right)$$
Multiply $3$ and $3$ to get $9$.
$$9=2\left(2x-1\right)$$
Use the distributive property to multiply $2$ by $2x-1$.
$$9=4x-2$$
Swap sides so that all variable terms are on the left hand side.