Problem solve of 1001 Extremely Basic

#include <stdio.h>
int main ()
{

    int A,B,X;
    A=10;
    B=9;
    X=A+B;
    printf("X=%d",X);

    return 0;
}







#include <stdio.h>
int main ()
{

    int A,B,X;
    A=-10;
    B=4;
    X=A+B;
    printf("X=%d",X);

    return 0;
}




#include <stdio.h>
int main ()
{

    int A,B,X;
    A=15;
    B=-7;
    X=A+B;
    printf("X=%d",X);

    return 0;
}