---

#include <iostream>
#include <cmath>
using namespace std;
int main() {
    double x, z1;
    cout <<"wedite x"<<endl;
    cin>>x;
    z1 = (x*x + 2*x - 3 + (x+1) * sqrt(x*x - 9)) / (x*x - 2*x - 3 + (x-1)*sqrt(x*x - 9));
    cout << z1;
    return 0;
}




#include <iostream>
#include <cmath>
using namespace std;
int main() {
    double x, z2;
    cout <<"wedite x"<<endl;
    cin>>x;
    z2 = sqrt((x+3) / (x-3));
    cout << z2;
    return 0;
}