Answer :

[tex]2 \sqrt{17-x} =2x-10\ \ \ \ \Rightarrow\ \ \ D:(17-x \geq 0\ \ \ and\ \ \ 2x-10 \geq 0)\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x \leq 17\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x \geq 5\\\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ D=<5;\ 17>\\\\2 \sqrt{17-x} =2(x-5)\ /:2\\\\ \sqrt{17-x} =x-5\ \ \ \Rightarrow\ \ \ (\sqrt{17-x})^2 =(x-5)^2\\\\17-x=x^2-10x+25\\\\[/tex]

[tex]x^2-9x+18=0\\\\ x^2-3x-6x+18=0\\\\x(x-3)-6(x-3)=0\\\\(x-3)(x-6)=0\ \ \ \ \Leftrightarrow\ \ \ (x-3=0\ \ \ \ or\ \ \ \ x-6=0)\\\\x=3\ \notin\ D\ \ \ \ \ \ \ \ \ \ \ x=6\ \in\ D\ \ \ \Rightarrow\ \ \ \frac{x}{4} = \frac{6}{4} =1.5\\\\Ans.\ \frac{x}{4} =1.5[/tex]