12 Write a C program to find x1+x2+x3+x4+ ….+xn.

#include<stdio.h>

#include<conio.h>

void main()

{

    int no,i,sum=0,x;

    clrscr();

    printf("enter number: ");

    scanf("%d",&no);

    printf("\nenter value of x: ");

    scanf("%d",&x);

    printf("\n\n");

    for(i=1; i<=no; i++)

    {

        printf("x%d + ",i);

        sum = sum + (x*i);

    }

    printf("\b\b\b = %d",sum);

    getch();

}

/*      output:

enter number: 6

enter value of x: 2

x1 + x2 + x3 + x4 + x5 + x6 = 42

*/