"
Please explain this code line by line
a. 4x1 + x2 - Xz = 5, --X1 + 3x2 + x3 = -4, 2x + 2x2 + 5x3 = 1. 6. Use the Jacobi method to solve the linear systems in Exercise 2, with TOL = 10-? in the lạ norm.