I need help implementing the following in C. I have made the the other function used for substitution, so it is the first part of the implementation I need help with.

1 #ifndef MATRIX. H 2 #define MATRIX. H 4 /* Structure representing a vector */ 5 typedef struct vector \ 6 7 8 vector_t; unsigned long n;/*length of vector double v; /* pointer to array of length n 10 /* Structure representing a matrix * 11 typedef struct matrix i 12 13 14 15J matrix_t; 16 17 #endif unsigned long m; unsigned long n; double* A /* number of rows /* number of columns /*pointer to two-dimensional array 1 #ifndef MATRIX. H 2 #define MATRIX. H 4 /* Structure representing a vector */ 5 typedef struct vector \ 6 7 8 vector_t; unsigned long n;/*length of vector double v; /* pointer to array of length n 10 /* Structure representing a matrix * 11 typedef struct matrix i 12 13 14 15J matrix_t; 16 17 #endif unsigned long m; unsigned long n; double* A /* number of rows /* number of columns /*pointer to two-dimensional array