#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
float mat[4][4],temp,temp1,x,y,z;
int i,n=3,j;
// clrscr();for(i=0; i<n; i++)
{
printf("\n\nenter the value of %d eqvation",i+1);
for(j=0; j<n; j++)
{
printf("\nenter the value of coeffcient %d: ",j+1);
scanf("%f",&mat[i][j]);
}
printf("\nenter the value of constent: ");
scanf("%f",&mat[i][j]);
}
printf("\n* * * Your Matrix * * *\n\n");
for(i=0;i<n;i++)
{
for(j=0;j<n+1;j++)
{
printf(" %g ",mat[i][j]);
}
printf("\n\n");
}
temp=mat[1][0]/mat[0][0];
temp1=mat[2][0]/mat[0][0];
for(i=0,j=0;j<n+1;j++)
{
mat[i+1][j]=mat[i+1][j]-(mat[i][j]*temp);
mat[i+2][j]=mat[i+2][j]-(mat[i][j]*temp1);
}
temp=mat[2][1]/mat[1][1];
temp1=mat[0][1]/mat[1][1];
for(i=1,j=0;j<n+1;j++)
{
mat[i+1][j]=mat[i+1][j]-(mat[i][j]*temp);
mat[i-1][j]=mat[i-1][j]-(mat[i][j]*temp1);
}
temp=mat[0][2]/mat[2][2];
temp1=mat[1][2]/mat[2][2];
for(i=0,j=0;j<n+1;j++)
{
mat[i][j]=mat[i][j]-(mat[i+2][j]*temp);
mat[i+1][j]=mat[i+1][j]-(mat[i+2][j]*temp1);
}
for(i=0;i<n;i++)
{
for(j=0;j<n+1;j++)
{
printf(" %.3f ",mat[i][j]);
}
printf("\n\n");
}
z = mat[2][3]/mat[2][2];
y = mat[1][3]/mat[1][1];
x = mat[0][3]/mat[0][0];
printf("\n\nx = %.3f",x);
printf("\n\ny = %.3f",y);
printf("\n\nz = %.3f",z);
getch();
}
/*
______________________________________
OUT PUT
______________________________________
enter the value of 1 eqvation
enter the value of coeffcient 1: 2
enter the value of coeffcient 2: 1
enter the value of coeffcient 3: 1
enter the value of constent: 10
enter the value of 2 eqvation
enter the value of coeffcient 1: 3
enter the value of coeffcient 2: 2
enter the value of coeffcient 3: 3
enter the value of constent: 18
enter the value of 3 eqvation
enter the value of coeffcient 1: 1
enter the value of coeffcient 2: 4
enter the value of coeffcient 3: 9
enter the value of constent: 16
* * * Your Matrix * * *
2 1 1 10
3 2 3 18
1 4 9 16
2.000 0.000 0.000 14.000
0.000 0.500 0.000 -4.500
0.000 0.000 -2.000 -10.000
x = 7.000
y = -9.000
z = 5.000
*/