Answer
$\frac{x-6}{4}$, $x\ne6$.
Work Step by Step
We must factor the top and bottom separately. First, we factor the top as $(x-6)(x-6)$. Then, we pull out 4 on the bottom, which gives us $4(x-6)$. This gives us the following fraction:
$\frac{(x-6)(x-6)}{4(x-6)}$
Then, we are allowed to cancel out the $x - 6$ factors.
This leads us to an answer of $\frac{x-6}{4}$. Even though there is no longer an $x - 6$ factor in the denominator, we must still declare that $x\ne 6$ because $x - 6$ was still initially in the bottom of the fraction.
