Answer
$3000$ disks
Work Step by Step
Replacing $f(x)$ with $5.10$ results to
\begin{array}{l}\require{cancel}
f(x)=3.3+\dfrac{5400}{x}
\\\\
5.10=3.3+\dfrac{5400}{x}
.\end{array}
Using the properties of equality to isolate $x$ results to
\begin{array}{l}\require{cancel}
5.10-3.3=\dfrac{5400}{x}
\\\\
1.8=\dfrac{5400}{x}
\\\\
x(1.8)=\left( \dfrac{5400}{x} \right) x
\\\\
1.8x=5400
\\\\
x=\dfrac{5400}{1.8}
\\\\
x=3000
.\end{array}
Hence, $3000$ disks must be produced.