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 $2x+1,3$.
$$3\left(x+3\right)=2\left(2x+1\right)$$
Use the distributive property to multiply $3$ by $x+3$.
$$3x+9=2\left(2x+1\right)$$
Use the distributive property to multiply $2$ by $2x+1$.