if else

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    double a, b, c, d;
    double y; 
    scanf("%lf%lf%lf%lf", &a, &b, &c, &d);
    double x = ( a * 2 + b * 3 + c * 4 + d ) / 10;
    printf("Media: %.1lf\n", x);
    if (x >= 7.0)
    {
    printf("Aluno aprovado.\n");
    }
    if (x < 5.0) 
    {
    printf("Aluno reprovado.\n");
    }
    if(x>=5.0&&x<=7.0){
        printf("Aluno em exame.\n");
        scanf("%lf", &y);
        printf("Nota do exame: %.1lf\n", y);
        double z = (x + y) / 2;
        if (z >= 5.0) printf("Aluno aprovado.\n");
        else 
        {
            printf("Aluno reprovado.\n");

        }
        printf("Media final: %.1lf\n", z);
    }
    return 0;
}