Question

(-i) (8+5i) =________________

(a) 8+5i

(b) -8-5i

(c) -5-8i

(d) 5-8i

This question was posed to me by my college professor while I was bunking the class.

I'd like to ask this question from Complex Numbers-2 in division Complex Numbers and Quadratic Equations of Mathematics – Class 11

Answer 1

The correct option is (d) 5-8i

For explanation I would say: (-i) (8+5i) = -8i – 5 i^2

= -8i -5(-1) = 5-8i.