#include <iostream.h>

void main()
{
float a,b,d,e;
cout<<"A: ";
cin>>a;
cout<<"B: ";
cin>>b;
cout<<"D: ";
cin>>d;
cout<<"E: ";
cin>>e;

float d1 = b-a;
float d2 = d*b-e;
float d3 = e-a*d;

cout<<"C1 = "<<d2/d1<<"; C2="<<d3/d1;

}