Question

como faço para resolver
A) (5 + 3i) (2+ 4i)

Answer 1

A)
$(5+3i)(2+4i)= \\ 10+20i+6i+12i^2= \\ 10+26i+12(-1)= \\ 10+26i-12= \\ -2+26i$

Answer 2

$Resolu\c{c}\~ao \to \left\{\begin{array}{ccc}(5+3i)*(2+4i)=\\\\10+20i+6i+12i^2 = \\\\10+20i+6i+12*(-1)=\\\\10+20i+6i-12=\\\\\boxed{\boxed{-2+26i}}\end{array}\right$

Obs: * = multiplicação.

Espero ter ajudado. :))