Answer:
A C++ program was used in creating two classes. the code is stated below.
Explanation:
Solution
The C++ program is executed below:
#include<iostream>
using namespace std;
//declare class (will be define later)
class Salesperson;
//class Sale
class Sale
{
   //private members of class
   private:
       string day;
       double amtOfSale;
       int salesPersonId;
  //public methods
   public:
       //constructor that takes day,amount of sale and salesPersonId as parameters
       Sale(string date,double sale,int id)
       {
           //set the private members to the initial values passed
           day=date;
           amtOfSale=sale;
           salesPersonId=id;
       }    
       //declare a friend function that takes objects of the two classes as parameters
       friend void display(Sale,Salesperson);
};  
//define class Salesperson
class Salesperson
{
   //private members of the class
   private:
       int salesPersonId;
       string lastName;    
   //public methods
   public:
       //constructor that takes name and id as parameters
       Salesperson(int id,string name)
       {
           //set the members of the class with the parameters passed
           salesPersonId=id;
           lastName=name;
       }  
       //declare a friend function that takes objects of the two classes as parameters
       friend void display(Sale,Salesperson);
};
//define the friend funtion
void display(Sale saleObj,Salesperson personObj)
{
   //display the sales info using the objects of the two classes
   cout<<"\nSale #"<<saleObj.salesPersonId<<" on "<<saleObj.day<<" for $"<<saleObj.amtOfSale<<" sold by #"<<personObj.salesPersonId<<" "<<personObj.lastName;
}  
int main()
{
   //create object for Sale class and pass default values
   Sale sObj1("12/25/2016",559.95,103);
   //create object for Salesperson class and pass default values
   Salesperson pObj1(103,"Woods");
  
   //create another object for Sale class and pass default values
   Sale sObj2("11/15/2016",359.95,106);
   //create another object for Salesperson class and pass default values
   Salesperson pObj2(106,"Hansen");
   //using the friend function dislay the sales info
   display(sObj1,pObj1);
   display(sObj2,pObj2);
   return 0;
}