PHP Code:
    double z; 
    double x = 2.229;
    int r=10,d=2; 
    double y=(int)((z=pow(r,d))*(x+(1/(2*z))))/z;
    cout<<y<<endl; 
1/2z not z/2
btw you have to swap the factors since first term evaluates first, and z is in the second - will cause the the addition to be in vain.