Question

Simplify the complex number.
(8i) (5) (-4-6i)

Answer 1

4th option

Explanation:

noting that i² = - 1

(8i)(5i)(- 4 - 6i)

= 40i²(- 4 - 6i)

= 40(- 1)(- 4 - 6i)

= - 40(- 4 - 6i) ← distribute parenthesis by - 40

= 160 + 240i

Answer 2

`(8i)(5i)(-4-6i)\\\\=40i^2(-4-6i)\\\\=-40(-4-6i)~~~;[i^2=-1]\\\\=160+240i`