Answer
$6$
Work Step by Step
We need to build a table of $ x $ values close to $9$ from the left side and right side and the values of $ f(x)$ for those values of $ x $.
$ x= 8.1..........., x= 9.00111111$
This gives:
$ f(x)= 5.846049894,......f(x)= 6.000185179$
From the table, we have
$\lim_\limits {x \to 9} \dfrac{9-x}{3-\sqrt x}=6$
