Here's the question you clicked on:
careless850
Simplify
\[\frac {x^{2}-16x+64}{x^{2}-64}\]
numerator is just (x - 8)^2 denominator is (x - 8)(x + 8) Canceling (x - 8) And you can get your simplified answer :)
I don't know where you guys are getting x-8 and x+8 from but ok
it is by factoring,the numerator is a perfect trinomial (x^2-2xy+y^2=(x-y)^2)