# How do you simplify (sqrt5-1)(sqrt5+3)?

Oct 20, 2017

$2 + 2 \sqrt{5}$

#### Explanation:

Expand the brackets by using the FOIL method.

Multiply the First terms, the outside terms, the inside terms and the last terms.

$\left(\sqrt{5} - 1\right) \left(\sqrt{5} + 3\right)$
$= 5 + 3 \sqrt{5} - \sqrt{5} - 3$
$= 2 + 2 \sqrt{5}$