## Algebra 1

$3\sqrt7-\sqrt{63}\longrightarrow$ factor the perfect square out of 63 =$3\sqrt7-\sqrt{9\times7}\longrightarrow$ multiplication property of square roots =$3\sqrt7-(\sqrt{9}\times\sqrt7)\longrightarrow$ simplify =$3\sqrt7-3\sqrt7\longrightarrow$ use distributive property =$\sqrt7(3-3)\longrightarrow$ simplify =$0\sqrt7\longrightarrow$ the product of any number and 0 is 0 =0