How do you simplify (sqrt5-2)(sqrt5-1)?

Apr 23, 2017

color(blue)(=7-3sqrt5

Explanation:

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

$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$\sqrt{5} - 2$
$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$\sqrt{5} - 1$
$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$- - - - - -$
$\textcolor{w h i t e}{a a a a a a a a a a a a a a a}$$5 - 2 \sqrt{5}$
$\textcolor{w h i t e}{a a a a a a a a a a a a a a a a a a}$$- \sqrt{5} + 2$
$\textcolor{w h i t e}{a a a a a a a a a a a a a}$$- - - - - -$
$\textcolor{w h i t e}{a a a a a a a a a a a a a a a}$color(blue)(5-3sqrt5+2

color(blue)(=7-3sqrt5