Answer:
The values of x that makes f(x) have a valid asymptote are 1 and 8
Explanation:
Given

Required
At what value does f(x) has a vertical asymptote
To solve this, we simply equate the denominator of f(x) to 0;
This is done as follows

This can be split to

Remove brackets

Make x the subject of formula in both cases



The values of x that makes f(x) have a valid asymptote are 1 and 8