## Algebra 2 Common Core

$3(x+5)(x-5)$
Factoring the $GCF=3,$ the given expression, $3x^2-75 ,$ is equivalent to \begin{align*}\require{cancel} & 3(x^2-25) .\end{align*} Using the factoring of the difference of $2$ squares which is given by $a^2-b^2=(a+b)(a-b),$ the expression above is equivalent to \begin{align*} & 3[(x)^2-(5)^2] \\&= 3[(x+5)(x-5)] \\&= 3(x+5)(x-5) .\end{align*} The factored form of the given expression is $3(x+5)(x-5) .$