Help me fix this code i cant run it

Question

#include<iostream>
using namespace std;
int main()
{switch (z) {
case 1:
z = (z + 10) * 25;
cout << x <<;
break;
case 2:
z = z - 10;
cout << x + 30 <<;
break;
case 3:
z = z - 10;
cout << z <<;
break;
default:
cout << z * z <<;
break;
}
return 0;
}

Answer 1

cout << something;

OR

cout << something << endl;

And you have to declare your variables first before using it to your program.
int x;
int z;

Answer 2

And also the variable "x".

Here, try to run this code, this is working because the x and z are declared beforehand and I added endl to each "cout". Excuse my indentions for now. If you want explanations, feel free to ask. Thanks!
https://code.sololearn.com/cA5A24A4a2a1

Answer 3

I cant run it even if i declare variable z