Untitled

#include<stdio.h>
#include<conio.h>

#define neq 3
void main () 
{
  float copvec[neq][neq + 1] = 
    { 
      {1, 1, 1, 3}, 
      {4, 3, 4, 8}, 
      {9, 3, 4, 7} 
    };
  
  float x[neq], sumofmultcoeffandx = 0, m;
  int i, j, k, l;
  
  for (k = 0, l= 0; k < neq - 1; k++, l++)
    for (i = k + 1; i < neq; i++)
      {
        m = copvec[i][l] / copvec[k][k];
        for (j = k; j < neq + 1; j++)
          copvec[i][j] = copvec[i][j] - m * copvec[k][j];
      }
  
  printf("\nThe Upper Triangular matrix including coefficient matrix and right side vector\n");
  
  for (i = 0; i < neq; i++)  
    {
      for (j = 0; j < neq + 1; j++)
        printf ("\t%f", copvec[i][j]);
      printf ("\n");
    }
  
  for (i = neq - 1; i >= 0; i--)
  {
      for (j = i + 1; j < neq; j++)
        sumofmultcoeffandx = sumofmultcoeffandx + copvec[i][j] * x[j];
      
      x[i] = (copvec[i][neq] - sumofmultcoeffandx) / copvec[i][i];
      sumofmultcoeffandx = 0;
  }
  
  printf ("\nThe evaluated values of variables");
  
  for (i = 0; i < neq; i++)
    printf ("\n\tx[%d]=%.2f", i, x[i]);
}