DEV C++ Küçük bir sorun

#include <stdio.h>
#include <conio.h>
		int a,b,c;
		void main () {
						a=3; 
						b=7; 
						c=a+b;
						printf("top=%d",c);
						getch();
		}

#include <stdio.h> 
 #include <conio.h> 
 #include <math.h> 
 		 int a,b,c,delta; 
 		 float z1,z2; 
 		 main () {	a=1; b=2; c=1; 
 		 	  	 	delta= bxb-4xaxc; 
 					z1=-b-sqry(delta))/(2 x a); 
 					z2=-b+sqry(delta))/(2 x a); 
 					printf("Birinci kok x1=%f \n ikinci kök x2=%f",x1,x2); 
 					getch();	 
 								 }

 
 #include <stdio.h> 
 #include <conio.h> 
 		int a,b,c; 
 		int main () { 
 						a=3;  
 						b=7;  
 						c=a+b; 
 						printf("top=%d",c); 
 						getch(); 
 		}

 
 #include <stdio.h>  
  #include <conio.h>  
  #include <math.h>  
  		 int a,b,c,delta;  
  		 float z1,z2;  
  		 int main () {	a=1; b=2; c=1;  
  		 	  	 	delta= b*b-4*a*c;  
  					z1=(-b-sqrt(delta))/(2 * a);  
  					z2=(-b+sqrt(delta))/(2 * a);  
  					printf("Birinci kok x1=%f \n ikinci kök x2=%f",z1,z2);  
  					getch();	  
  								 }

#include<stdio.h> 
 #include<conio.h> 
 int main() 
 { 
 	int a,b,c; 
 	a=3; 
 	b=7; 
 	c=a+b; 
 	printf("toplam= %d",c); 
 	getch(); 
 }