Bunyakovsky:
\(\left(\sqrt{x+5}+\sqrt{2-x}\right)^2\le\left(1^2+1^2\right)\left(x+5+2-x\right)=2.7=14\)
\(\Rightarrow\sqrt{x+5}+\sqrt{2-x}\le\sqrt{14}\Leftrightarrow x^2-25\le\sqrt{14}\)
\(\Rightarrow x^2\le\sqrt{14}+25\)
\(\Rightarrow-\sqrt{\sqrt{14}+25}\le x\le\sqrt{\sqrt{14}+25}\)