% Linear Algebra: Theory and Applications
% Ward Cheney & David Kincaid
% JBPub.com (c) 2008 
% File: exp8211.m
% Example 8.2.11

A = [4.,7.,-3.; 2.,-4.,6.; -3.,2.,5.; 1.,-2.,4.]
b = [1.; 5.; 7.; -3.]
[Q, R] = qr(A)
x = R$\Q'*b
e = A'*R