Functions and More Functions

Calculus Level 1

$\frac { f\big( \sqrt { 6 } \big) -f\big( \sqrt { 8 } \big) }{ \sqrt { 6 } -\sqrt { 8 } }$

Given the function $f\left( x \right) =\frac { 3 }{ 5 } x+\sqrt { 3 },$ evaluate the expression above.