So far this is what i got:

Original eq:

f(x)=(x+5)/(x^2-16)

By using quotient rule i got:

f'(x)=0=x^2-16-2x^2-10x

0=(x+8)(x+2)

x=-8, x=-2

Now subbing them back into f(x) i got max and min as (correct me if im wrong):

(-8,3/80) and (-2, -3/20)

Point of inflection:

f''(x)=2(x^3+15x^2+48x+80)/(x^2-16)^3

the second derivative is right im pretty sure i just took out 2 as common factor:

Now this is where im confused do i make the whole thing equal 0, or the top line? and how can i simplify it afterwards?