Answer:
[tex]0 < x < 15, 0 < f(x) < 675[/tex]
Step-by-step explanation:
The value of x associated with maximum allowable length is:
[tex]x_{max} = \frac{90\,ft}{6}[/tex]
[tex]x_{max} = 15[/tex]
The maximum packaging cost is:
[tex]f(x_{max})= 3\cdot (15)^{2}[/tex]
[tex]f(x_{max}) = 675\,cents[/tex]
The domain and range values for this function are, respectively:
[tex]0 < x < 15, 0 < f(x) < 675[/tex]