Answer:
[tex]\textbf{$x \in (-\infty, 3] $}\\[/tex]
Step-by-step explanation:
[tex]\textup{Given:}\\$ 4x + 6 $\textup{Subtracting $6$ from both the sides }\\$ 4x \leq 18 - 6 \hspace{5mm} (=12) $\\\textup{Dividing by $4$ on both the sides: \hspace{15mm} [Note that the sign of the inequality changes only when we divide it by a negative number]}\\$ x \leq 3 $\\\textup{$x$ can be any real number less than or equal to 3.}\\$ \iff x \in R^- \cup \{a : 0 \leq a \leq 3\} $[/tex]