Use the geometric definition of the cross product and the properties of the cross product to make the following calculations.

(a) $((\vec{i} + \vec{j}) \times \vec{i} ) \times \vec{j}$ =

(b) $( \vec{j} + \vec{k} ) \times ( \vec{j} \times \vec{k} )$ =

(c) $4 \vec{i} \times ( \vec{i} + \vec{j} )$ =

(d) $( \vec{k} + \vec{j} ) \times ( \vec{k} - \vec{j} )$ =