Simplify (6x-18)/(x^2-4)*(x^2+5x+6)/(x^2-9)

Factor ${\displaystyle 6}$ out of ${\displaystyle 6x}$.

Factor ${\displaystyle 6}$ out of ${\displaystyle -18}$.

Factor ${\displaystyle 6}$ out of ${\displaystyle 6x+6\cdot -3}$.

Rewrite ${\displaystyle 4}$ as ${\displaystyle 2^2}$.

Since both terms are perfect squares, factor using the difference of squares formula, ${\displaystyle a^2-b^2=(a+b)(a-b)}$ where ${\displaystyle a=x}$ and ${\displaystyle b=2}$.

Consider the form ${\displaystyle x^2+bx+c}$. Find a pair of integers whose product is ${\displaystyle c}$ and whose sum is ${\displaystyle b}$. In this case, whose product is ${\displaystyle 6}$ and whose sum is ${\displaystyle 5}$.

Write the factored form using these integers.

Rewrite ${\displaystyle 9}$ as ${\displaystyle 3^2}$.

Since both terms are perfect squares, factor using the difference of squares formula, ${\displaystyle a^2-b^2=(a+b)(a-b)}$ where ${\displaystyle a=x}$ and ${\displaystyle b=3}$.

Cancel the common factor of ${\displaystyle x-3}$.

Cancel the common factor of ${\displaystyle x+2}$.

Multiply ${\displaystyle \frac{6}{x-2}}$ by ${\displaystyle \frac{x+3}{x+3}}$.

Cancel the common factor of ${\displaystyle x+3}$.