Simplify (x^2-8x+12)/(x^2-16)*(4x+16)/(x^2-4x+4)

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 ${\displaystyle 12}$ and whose sum is ${\displaystyle -8}$.

Write the factored form using these integers.

Rewrite ${\displaystyle 16}$ as ${\displaystyle 4^2}$.

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 ${\displaystyle b=4}$.

Factor ${\displaystyle 4}$ out of ${\displaystyle 4x}$.

Factor ${\displaystyle 4}$ out of ${\displaystyle 16}$.

Factor ${\displaystyle 4}$ out of ${\displaystyle 4x+4\cdot 4}$.

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

Check that the middle term is two times the product of the numbers being squared in the first term and third term.

Rewrite the polynomial.

Factor using the perfect square trinomial rule ${\displaystyle a^2-2ab+b^2={(a-b)}^2}$, where ${\displaystyle a=x}$ and ${\displaystyle b=2}$.

Combine.

Cancel the common factor of ${\displaystyle x-2}$ and ${\displaystyle {(x-2)}^2}$.

Cancel the common factor of ${\displaystyle x+4}$.

Move ${\displaystyle 4}$ to the left of ${\displaystyle x-6}$.