Question 529800
(1+2i)(1-2i) =

1 x 1 = 1

1 x -2i = -2i

2i x 1 = 2i

2i x (-2i) = -4(i^2)

1 - 2i + 2i -4(i^2)

1 - 4(-1) =

1 + 4 = 5


The answer is 5.