Question

Efetue: (-5+2i).(-5+2i)

Answer 1

(-5+2i)(-5+2i)=
+25-10i-10i+4i^2=
+25-20i+4.(-1)=
+25-4-20i=
+21-20i

Answer 2

(-5+2i)×(-5+2i) = -5×(-5)+(-5×2i)+2i×(-5)+2i×2i =
=25-10i-10i+4i2 (i ao quadrado)=
=25-20i+4×(-1)=
25-20i-1=
24-20i