Chapter 8.6, Problem 86STP

(a)

To determine

To find: The equation of the cost for $x$ number of doors.

Answer to Problem 86STP

The equation of the cost of doors is $(85+25 $x$ ).

Explanation of Solution

Given information:

The given cost of service call is $\text{85}\$$ , door is $\text{25}\$$ and lock is $30\$.$

Calculation:

Consider the locksmith charges $\text{85}\$$ for each call, $\text{25}\$$ for each lock

Consider $x$ number of door need to be serviced

Therefore, the total charge is

Total Charge = charge for service call +total charge for $x$ door

  $\begin{array}{c}\text{Total}\text{Charge}=\$(85+30\times 4)\\ =\$205\end{array}$

Therefore the total charge is $\$(\text{85}+\text{25})$

(b)

To determine

To find: The cost of which locks changed.

Answer to Problem 86STP

The total charge is 205$.

Explanation of Solution

Given information:

The given cost of service call $\text{85}\$$ ,door is $\text{25}\$$ and $30\$.$

Calculation:

Consider front, side, back and garage door lock are need to be change that is total number of lock is $4$ .therefore, the total charges is:

Total Charge = charge for service call + lock charge for four door

  $\begin{array}{c}\text{Total Charge}=\$(85+30\times 4)\\ =\$205\end{array}$

Therefore, the total charges are $\text{2}0\text{5}\$$ .