Question

Someone help me on this.

Answer 1

`-57-39i`

Explanation:

So we have the expression:

`(7+2i)(-9-3i)`

FOIL:

`=7(-9)+7(-3i)+2i(-9)+2i(-3i)`

Simplify:

`=-63-21i-18i-6i^2`

Recall that i² is just -1. Thus:

`=-63-21i-18i-6(-1)`

Simplify:

`=-63-21i-18i+6`

Combine like terms:

`=(-63+6)+(-21i-18i)`

Add:

`=-57-39i`

And we're done!