Question

multiply, answer in a+bi form:
(4-5i)^2

Answer 1

(4-5i)^2 = (4-5i)(4-5i)



(4-5i)^2 = 4*4+4*(-5i)+(-5i)(4)+(-5i)(-5i)



(4-5i)^2 = 16-20i-20i+25i^2



(4-5i)^2 = 16-20i-20i+25(-1)



(4-5i)^2 = 16-20i-20i-25



(4-5i)^2 = -9-40i