Answer:
The system of equation to find the length of service call is
.
The length of service call for which both businesses charge the same amount is 5 hours.
Step-by-step explanation:
Given:
Let the 'x' represents number of hours of labor.
Also Let the 'y' represent the Total charge.
For Business A:
Fixed charge = $50
Charge of labor for each hour = $36
Amount of total charge is the sum of fixed charge and charge of labor for each hour multiplied number of hours of labor
framing in equation form, we get;

For Business B:
Fixed charge = $35
Charge of labor for each hour = $39
Amount of total charge is the sum of fixed charge and charge of labor for each hour multiplied number of hours of labor
framing in equation form, we get;

Hence The system of equation to find the length of service call is
.
Now to find the length of service call for which both businesses charge the same amount, we will make both the equation equal we get;

Now we solve the equation,
Combining the like terms, we get;

Dividing both side by '3' using division property, we get;

Hence The length of service call for which both businesses charge the same amount is 5 hours.