let $a,b,c\in\mathbb{Z}[i]$such that a=bc and say $|b|=B$ and $|c|=C$ . prove or disprove, there is no other decomposition such: $a=de ,|d|=B,|e|=C$ up to multiplying b and c by unity.
Edit: this claim is not true for complex number, but is it for reals? prove it!
No it doesn't hold for real number either: counterexample: $25=(4+3i)(4-3i)=5*5$ yet $(4+3i)$ has the same norm as $5$, as well $(4-3i)$ and $5$.