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[10][10], m, temp[10];
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

I am Abhishek from Lucknow (India). I have been working as a software engineer from last 6+ years, and its my passion to learn new things and implement them as a practice.

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