## Algebra 1

$-7\sqrt5$
$3\sqrt{45}-8\sqrt{20}\longrightarrow$ factor the perfect squares out of 45 and 20 =$3\sqrt{9\times5}-8\sqrt{4\times5}\longrightarrow$ multiplication property of square roots =$3(\sqrt{9})(\sqrt5)-8(\sqrt{4})(\sqrt5)\longrightarrow$ simplify =$3(3)(\sqrt5)-8(2)(\sqrt5)\longrightarrow$ multiply =$9\sqrt5-16\sqrt5\longrightarrow$ use distributive property =$\sqrt5(9-16)\longrightarrow$ simplify =$-7\sqrt5$