Given the function:
[tex]A(t)=256-16t[/tex]
Where A is the amount of money (in dollars) Diane has left in her account after t trips on the toll roads.
(a)
After 8 trips on the toll roads (t = 8):
[tex]\begin{gathered} A(8)=256-16(8)=256-128 \\ \\ \therefore A(8)=\$128 \end{gathered}[/tex]
(b)
If her account is empty:
[tex]\begin{gathered} A(t)=0 \\ \\ \Rightarrow256-16t=0 \end{gathered}[/tex]
Solving the equation for t:
[tex]\begin{gathered} 256=16t \\ \\ \therefore t=16\text{ trips} \end{gathered}[/tex]
