4. The system of equations has an approximate solution x1 +0.33x2 = 1 0.5x1 0.09x2 = 1 3.2 x = -6.67 (a) Find the residual error r b Ax with respect to x. (b) Find a solution to Ay =r where A is the system matrix for the original system of equations and r is the residual error from part (a). (c) Determine if x y provides a better approximation to the original system of equations. If one of them does, propose a method to reduce the error even further.