Answer
$-20$
Work Step by Step
Using the properties of radicals, the given expression, $
(\sqrt{5}+5)(\sqrt{5}-5)
,$ simplifies to
\begin{array}{l}\require{cancel}
(\sqrt{5})^2-(5)^2
\\\\=
5-25
\\\\=
-20
.\end{array}
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.