Respuesta :

(3 - 2i)(3 + 2i) . Its form is (a - b)(a + b) = a² -  b²
( a = 3  and b = 2i)

(3)² - (2i)²
 = 9 - (4i²)  ,  but 1² = -1
 = 9 - (-4) = 9+4  = 13

So   (3-2i)(3+2i)  = 13