13........................

Answer:
Choice c is the answer.
Step-by-step explanation:
We have given a expression.
[tex]\frac{\sqrt{x} }{\sqrt{x}+\sqrt{5}}[/tex]
We have to find the rationalized form of above expression.
Multiplying and dividing by [tex]\sqrt{x}-\sqrt{5}[/tex] to given expression,we have
[tex]\frac{\sqrt{x} }{\sqrt{x}+\sqrt{5} } \frac{\sqrt{x}-\sqrt{5} }{\sqrt{x}-\sqrt{5} }[/tex]
[tex]\frac{\sqrt{x}(\sqrt{x}-\sqrt{5})}{(\sqrt{x})^{2}-(\sqrt{5})^{2}}[/tex]
[tex]\frac{(\sqrt{x})^{2}-\sqrt{5}\sqrt{x}}{x-5}[/tex]
[tex]\frac{x-\sqrt{5x} }{x-5}[/tex] which is the rationalized form of given expression.