Answer
$$
(2\mathbf{i}-3 \mathbf{j}+4\mathbf{k}) \times(\mathbf{i}+\mathbf{j}-7\mathbf{k})\\
=17\mathbf{i}+18\mathbf{j}+5\mathbf{k}
$$
Work Step by Step
$$
(2\mathbf{i}-3 \mathbf{j}+4\mathbf{k}) \times(\mathbf{i}+\mathbf{j}-7\mathbf{k})\\=2( \mathbf{k}+7\mathbf{j})-3(-\mathbf{k}-7\mathbf{i})+4(\mathbf{j}-\mathbf{i})\\
=17\mathbf{i}+18\mathbf{j}+5\mathbf{k}
$$
