# How do you find the value of a if 2i is a root of z^3-2z^2i+az-32i=0?

Hence it is a root just replace the value of $z$ with $2 i$ so we get
(2i)^3-2(2i)^2i+a(2i)-32i=0=> -8i+8i+2ia-32i=0=> 2i(a-16)=0=>a=16