(1-i)³
=(1-i)(1-i)(1-i)
=(1×1-1×i-i×1+i×i)(1-i)
=(1-i-i+i²)(1-i)
=1×1-1×i-i×1+i×i-i×1+i×i+i²×1-i²×i
=1-i-i+i²-i+i²+i²-i²
=1-3i+2i²
(1-i)³
=(1-i)(1-i)(1-i)
=(1×1-1×i-i×1+i×i)(1-i)
=(1-i-i+i²)(1-i)
=1×1-1×i-i×1+i×i-i×1+i×i+i²×1-i²×i
=1-i-i+i²-i+i²+i²-i²
=1-3i+2i²