$$\frac{(3√5+√125)}{(√80+6√5)}$$​ is:

Given:
​$$\frac{(3√5+√125)}{(√80+6√5) }$$ 

Concept Used:​

A rational number is any number that can be expressed in the form of a fraction:

Rational Number = $$\frac{p}{q}$$​​

Where:

p and q are integers,

q≠0 (the denominator cannot be zero). 

​$$\frac{3\sqrt5 + \sqrt{125}}{\sqrt{80}+6\sqrt5} \\ \ \\ = \frac{3\sqrt5 + 5\sqrt{5}}{4\sqrt{5}+ 6\sqrt5} \\ \ \\ = \frac{8\cancel{\sqrt5} }{10\cancel{\sqrt{5}}} \\ \ \\ = \frac{4}{5}$$ 

this is a rational number.