You can also find the boundary values by solving
 \qquad \implies \qquad 4x &= -2 \qquad \implies \qquad x = -\frac{1}{2} \end{align*})
Then, consider values in each of the three possible regions,
x < -1/2, -1/2 <
x < 3, and
x > 3, where the inequality given in the question is true, false, and true (respectively), giving the solution as:

Or, in interval notation,
)