The two numerical expressions in the given equation can be simplified as √9=3 and √64=8 ,so the equation can be rewritten as √x=3=8,or √x=5 Squaring both sides of the equation gives x=25. Choice A is incorrect and may result from a misconception about how to square both sides of √x=5 to determine the value of x.Choice B is incorrect. The value of √x,not x is 5. Choice D is incorrect and represents a misconception about the properties of radicals. While it is true that 55+9=64, it is not true that √55+√9=√64