#include <stdio.h>
#include <math.h>
#include <conio.h>
void main()
{
 double a[5][6]={1,0,1,0,-1,0,
				 0,0,1,-1,1,0,
				 0,4,0,10,0,10,
				 0,0,6,10,0,15,
				 2,0,0,10,0,5};
 int n,i,j,k;
 n=5;
 for (k=0;k<n;k++)
 for(j=k+1;j<=n;j++){
   a[k][j]=a[k][j]/a[k][k];
   for (i=0;i<n;i++) if (i!=k)
   a[i][j]=a[i][j]-a[i][k]*a[k][j];
					}
 printf ("i1=%f i2=%f i3=%f i4=%f i5=%f\n",a[0][n],a[1][n],a[2][n],a[3][n],a[4][n]);
 getch();
}