Question

Z= 9-4i e W= 10-2i Determine z.w.

Answer 1

z.w=(9-4i).(10-2i)

9.10-9.(-2i)-4i.10-(-4i.-2i)
90-18i-40i+8i^2
90-58i-8
82-58i

Lembrando que i^2= -1
:)