Ответ: z=(8+2i)/(5-3i)=(8+2i)(5+3i)/[(5-3i)(5+3i)]=(40+24i+10i-6)/(25+9)=
=(34+34i)/34=1+i
|z|=√(1+1)=√2
argφ=arctg1
φ=Π/4