**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.**