\[1)\ (1 + i)^{8} = \left( 1 + 2i + i^{2} \right)^{4} =\]
\[= (1 + 2i - 1)^{4} = (2i)^{4} =\]
\[= \left( 4i^{2} \right)^{2} = ( - 4)^{2} = 16;\]
\[2)\ (1 - i)^{12} = \left( 1 - 2i + i^{2} \right)^{6} =\]
\[= (1 - 2i - 1)^{6} = ( - 2i)^{6} =\]
\[= \left( 4i^{2} \right)^{3} = ( - 4)^{3} = - 64.\]