Question

What is the product of the complex numbers below?
(3-9i)(6-i)

Answer 1

(9-57i)

Explanation:

We need to find the product of the given complex number i.e.

(3-9i)(6-i)

It can be solved as follows :

(3-9i)(6-i) = 3(6) +3(-i) +(-9i)(6) + 9i(i)

= 18-3i-54i+9i²

We know that, i² = -1

So,

= 18-3i-54i+9(-1)

= 18-57i-9

= 9-57i

So, the product of the given complex number is (9-57i).