Variable $x$ cannot be equal to $0$ since division by zero is not defined. Multiply both sides of the equation by $4x$, the least common multiple of $4,x,2$.
$$x=4\times 3+4x\left(-\frac{1}{2}\right)$$
Multiply $4$ and $3$ to get $12$.
$$x=12+4x\left(-\frac{1}{2}\right)$$
Express $4\left(-\frac{1}{2}\right)$ as a single fraction.
