# Thread: Complex Numbers

1. ## Complex Numbers

I can factor everything up until i get to the last two terms that require me to multipy the square roots and there after... Thanks in advance for any help!!

(-5+sqrt(-9)) (7-sqrt(-1))

2. Originally Posted by tarabshort
I can factor everything up until i get to the last two terms that require me to multipy the square roots and there after... Thanks in advance for any help!!

(-5+sqrt(-9)) (7-sqrt(-1))
$\displaystyle (-5 + \sqrt{-9})(7 - \sqrt{-1})$

$\displaystyle (-5 + 3i)(7 - i)$

$\displaystyle -35 + 5i + 21i - 3i^2$

$\displaystyle -35 + 26i + 3$

$\displaystyle -32 + 26i$

3. Originally Posted by tarabshort
I can factor everything up until i get to the last two terms that require me to multipy the square roots and there after... Thanks in advance for any help!!

(-5+sqrt(-9)) (7-sqrt(-1))
Hi tarabshort,

Here are the steps to multiply these 2 complex expressions:

$\displaystyle (-5+\sqrt{-9})(7-\sqrt{-1}=$

$\displaystyle (-5+3i)(7-i)=$

$\displaystyle -5(7-i)+3i(7-i)=$

$\displaystyle -35+5i+21i-3i^2=$

$\displaystyle -35+26i+3=$

$\displaystyle -32+26i$

Edit: I'm too slow today, Skeeter. I'm using a dial-up connection.