Q1. (Gaussian elimination) Write a python code for solving a system of linear equations by Gaussian elimination. Written in matrix form, a system of linear equations is expressed as Ax= b. 1. Define a function forward_elim(a, b) which takes in A and b, does forward elimination, and returns the new A and b after foward elimination. 2. Define a function backward_subs (A, b) which takes in the A and b obtained by foward elimination, does backward substitution, and returns the solution x. 3. Define a function gaussian_elim(a, b) which takes in the initial A and b and returns the solution x. In this function, we need to call the two functions defined in Q1.1 and Q1.2. 4. Apply the function gaussian_elim(A, b) defined in Q1.3 to solve the following equations: 1 2 ( -1 :) 0-0 1 1 3