Answer:
[tex]0 \leq x \leq 3[/tex]
Step-by-step explanation:
Given
[tex]f(x) = 25x + 60[/tex]
Required
Determine the domain
The domain, in this case means the possible values of x
From the question, we understand that x represents minutes
Since it's impossible to have a negative minutes, then x starts at 0
i.e. [tex]x \geq 0[/tex] or [tex]0 \leq x[/tex]
Also, from the question, we understand that the time can not be more than 3 minutes
i.e.
[tex]x \leq 3[/tex]
Now, we have two inequalities:
[tex]0 \leq x[/tex] and [tex]x \leq 3[/tex]
Which can be written as:
[tex]0 \leq x \leq 3[/tex]
Hence, the domain is: [tex]0 \leq x \leq 3[/tex]