# Gauss Elimination method in C language using Lower triangular matrix

This is a simple C language program that calculates solution of n-linear equations using Non-pivotal Gauss Elimination method. It uses lower triangular matrix to do so, for upper triangular matrix visit here.

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

float matrix, m, temp;
int i, j, k, n;

void lower_traingularisation() {
for (i=n-1; i>0; i--)
for (j=i-1; j>=0; j--) {
m	= matrix[j][i]/matrix[i][i];
for (k=0; k<n+1; k++) {
matrix[j][k]	= matrix[j][k]-(m*matrix[i][k]);
}
}
} //lower_traingularisation

void back_subsitution() {
for (i=0; i<n; i++) {
m	= matrix[i][n];
for (j=0; j<i; j++)
m	= m - temp[j] * matrix[i][j];
temp[i]	= m/matrix[i][i];
printf("\n x%d => %f", i+1, temp[i]);
}
} // back_subsitution

void main() {
printf("Enter number. of variables :: ");
scanf("%d", &n);

printf("Enter the augmented matrix: \n");
for (i=0; i<n; i++)
for (j=0; j<n+1; j++)
scanf("%f", &matrix[i][j]);

lower_traingularisation();

printf("The lower traingular matrix is : \n");

for (i=0; i<n; i++) {
for (j=0; j<n+1; j++)
printf("%f \t", matrix[i][j]);
printf("\n");
}

printf("The required result is : \n");

back_subsitution();

getch();
} // main```