#!/usr/bin/python3 import numpy as np n = 10 a = -np.eye(n)/2 - np.eye(n, k=1)/2 + np.eye(n, k=2) a[-2:, -2:] = np.eye(2) b = np.zeros(n) b[-2] = 426 b[-1] = 427 x = np.linalg.solve(a, b) print(x[:2])