Matlab Homework

A = [1, 0, 0; 1, 1, 0; 1, 0, 1; 0, 1, 1; 0, 0, 1]
c = [280; 390; 400; 210; 118]

%% QR Decomposition
[Q, R] = qr(A);
R0 = zeros(3,3);
d = transpose(Q)*c;
d0 = [0; 0; 0];
for i = 1 : 3
   for j = 1 : 3
      R0(i,j) = R(i,j);
   end
   d0(i,1) = d(i,1);
end
x1 = d0\R0

%%  "\"
x2 = c\A