(i) u=5i−j+k;v=j−5k;w=−15i+3j−3k\mathbf{u} = 5\mathbf{i} - \mathbf{j} + \mathbf{k}; \mathbf{v} = \mathbf{j} - 5\mathbf{k}; \mathbf{w} = -15\mathbf{i} + 3\mathbf{j} - 3\mathbf{k}u=5i−j+k;v=j−5k;w=−15i+3j−3k