Answer
(i) $\dfrac{f(x)}{g(x)}=5x-1+\frac{6}{x}$
(ii) The domain of $\dfrac{f(x)}{g(x)}$ does not include 0.
Work Step by Step
Divide $f(x)$ by $g(x)$ to have:
$\dfrac{f(x)}{g(x)} = \dfrac{25x^2-5x+30}{5x}$
$\dfrac{f(x)}{g(x)} = 5x-1+\frac{6}{x}$
Since $5x$ is in the denominator of the original quotient, and a denominator is not allowed to be zero, then
$5x \ne 0
\\x \ne 0$
