the columns a1 and a2 of [2 2 1; -1 2 2] '

For the first column a1 [2 2 1]^T, follow the Householder steps to construct r1,w1,u1, and H1. The second column of H1A still needs work, on and below the diagonal (call those two components a2=[-1 2 2]^T). Follow the same steps to construct r2, w2, u2, and H2 (with first row [1 0 0] ). Then, find H2*H1*A = Q^-1*A = upper triangular R.