Revising quadratic equation

it is showing task 1 is ok but ask 2 and 3 are failed. can someone help me out pease
#include
#include
using namespace std;
int main() {
float a, b, c, x1, x2, d;
cin >> a >> b >> c;
d = bb - 4a*c;

if (d > 0) {
    x1 = (-b + sqrt(d)) / (2*a);
    x2 = (-b - sqrt(d)) / (2*a);
    cout << "real and distinct" << endl;
    cout << x1 <<" " << x2;
}

else if (d == 0) {
    cout << "real and equal" << endl;
    x1 = (-b + sqrt(d)) / (2*a);
    cout << x1;
}
else 
    cout << "imaginary";
return 0;

}