Answer
$30+0i$
Work Step by Step
We are given the expression $(\sqrt 5-5i)(\sqrt 5+5i)$. We can use the FOIL method to simplify.
F=$\sqrt 5\times\sqrt 5=(\sqrt 5)^{2}=5$
O=$\sqrt 5\times5i=5i\sqrt 5$
I=$-5i\times\sqrt 5=-5i\sqrt 5$
L=$-5i\times5i=-25i^{2}=-25\times-1=25$
Now,we can combine these terms.
$(25)+(-5i\sqrt 5)+(5i\sqrt 5)+(5)=30=30+0i$
We know that $i^{2}=-1$.
