Question

evaluate (-4+i)(-4-i)

I get to
16+4i-4i-i^2

But I'm a little confused, please help!!

Answer 1

I get 16-i^2... So you basically distribute everything.
So first, you'd do -4(-4-i) which gets you 16+4i
Next, you do i(-4-i) which gets you -4i-i^2
When you add like terms, (-4i+4i), you're left with 16-i^2. 
So 16-i^2 would be your answer.