How do I solve (16i) (5i)

(16i) (5i)

Since multiplication order does not matter and everything is multiplication, we can multiply the i together and the 16 and 5 together.

Since 16 * 5 = 80, we have 80i · i.

Since i · i = i², and i² = - 1 (it's the imaginary unit), we have our final answer of

-80