Python code for backward substitution method for solving the linear system

Description

This function uses the backward substitution method for solving the linear system Ax = b, where A is an upper triangular matrix b is a known vector and n is the dimension of the problem.

Example :

A = np.diag([2, -1, 3])

b = np.array([4, -1, 3])

Final result of the python code

x =
[[ 2.]
[ 1.]
[ 1.]]