/* Root of ax + b = 0  */ 
#include <iostream> 
#include <cstdlib>
#include <cmath> 

using namespace std;

int main(int argc, char *argv[])
{char ans;
 double a, b, root; 
 cout<<"Do you want to solve an equation (y/n): "; 
 cin>>ans;
 while (ans=='y') // zero or more equations
 {
   do {
    cout<<"Input the coefficients a, b of the equation."<<endl;
    cout<<"Coefficient a must not be zero: "; 
    cin>> a >> b;    
   } while (a==0);
   cout<< "Coefficients are "<<a<<", "<<b<<endl; 
   /* compute the root */ 
   if (b==0) root=0; else root= -b/a; 
   /* print the root */
   cout<< "Root: "<<root<<endl;
 cout<<"Do you want to solve an equation (y/n): "; 
 cin>>ans;  
}
 system("PAUSE");
 return 0;  
}