Одз:
0 \\ x>0 \end{array}\right.\Rightarrow \left\{\begin{array}{cc} |x|<\sqrt{12} \\ x>0 \end{array}\right.\Rightarrow \ x\in (0;2\sqrt{3})" alt="\left\{\begin{array}{cc} 12-x^2>0 \\ x>0 \end{array}\right.\Rightarrow \left\{\begin{array}{cc} |x|<\sqrt{12} \\ x>0 \end{array}\right.\Rightarrow \ x\in (0;2\sqrt{3})" align="absmiddle" class="latex-formula">
решаем:
Ответ: x=3