Answer :
(x - 4)/(x + 4)
Step-by-step explanation:
[tex]\begin{aligned}\tt\frac{x^2-16}{x^2+8x+16}&=\tt\frac{x^2-4^2}{\left(x+4\right)^2}\\&=\tt\frac{\left(x+4\right)\left(x-4\right)}{\left(x+4\right)^2}\\&=\tt\frac{x-4}{x+4}\end{aligned}[/tex]
Note :
- a² - b² = (a + b)(a - b)
- (a + b)² = a² + 2ab + b²