Question

Someone help me on this.

Answer 1

Answer:

$-57-39i$

Step-by-step 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!