12}} \right. \Rightarrow~~~\\ \\ \\ \Rightarrow~~~~ \left \{ {{-1 \leq x \leq 4} \atop {x > 3}} \right. ~~~\Rightarrow~~~~ \boxed{x \in (3;4]}" alt="\displaystyle \left \{ {{x^2-3x-4 \leq 0} \atop {12-4x\ \textless \ 0}} \right. \Rightarrow~~ \left \{ {{(x+1)(x-4) \leq 0} \atop {4x > 12}} \right. \Rightarrow~~~\\ \\ \\ \Rightarrow~~~~ \left \{ {{-1 \leq x \leq 4} \atop {x > 3}} \right. ~~~\Rightarrow~~~~ \boxed{x \in (3;4]}" align="absmiddle" class="latex-formula">