Ошибка в count<<x;

#include <iostream>
 
int main(int argc, const char * argv[]) 
{
    // insert code here...
    using namespace std;
    cout << "Good morning, my Master. Lets work together today!\n";
    cout<<"a=";
    int a;
    cin>>a;
    cout<<"b=";
    int b;
    cin>>b;
    int x;
    if (a!=0) x=-b/a;
    if (b==0) x=0;
    cout<<x;
    return 0;
}

float x;
if (a == 0)
{
    cout << "x = infinity" << endl;
    return 0;
}
else if (b == 0) x = 0;
else x = (float)-b / a;
cout << "x = " << x << endl;

#include <iostream>
int main(int argc, const char * argv[]) 
{
    using namespace std;
    cout << "Good morning, my Master. Lets work together today!\n";
    cout<<"a= ";
    int a;
    cin>>a;
    cout<<"b= ";
    int b;
    cin>>b;
    int x;
    if (a) 
    cout<<"x= "<<-b/a<<endl;
    else if (b==0) 
    return 0;
    else
    cout<<"Error!";
    return 0;
}

#include <iostream>
int main() {
    // insert code here...
    using namespace std;
    cout << "Good morning, my Master. Lets work together today!\n";
    cout<<"a=";
    int a;
    cin>>a;
    cout<<"b=";
    int b;
    cin>>b;
    cout<<"c=";
    int c;
    cin>>c;
    int x;
    x=0;
    if (a==0)
    {
        x=-c/b; cout<<x;
    }
    if (b==0)
    {
        x=(-c/a)^1/2; cout<<x;
    }
    if (a==0||b==0) cout<<"beskonechnoe mnojestvo reshenii";
    else
    {
    int D;
    D=b^2-4*a*c;
    if (D<0) cout<<"net reshenii\n";
    if (D==0) cout<<"x="<<-b/2*a;
    if (D>0)
    {
        int x1;
        int x2;
        x1=(-b+D^1/2)/2*a;
        x2=(-b-D^1/2)/2*a;
        cout<<"x1="<<x1<<endl;
        cout<<"x2="<<x2<<endl;
    }
    
    }
    return 0;
}

x=(-b+sqrt(D))/(2.0*a);