Q$13.$ The function $f(x)=\frac{x+6}{-2x-5}$ is:

a$)$ Increasing on the interval $(-1,10)$ and decreasing on $t$

b$)$ Decreasing on the intervals $(-,-1)$ and $(10,)$ and

c$)$ Decreasing on $(-,).$

d$)$ Increasing on $(-,\frac{-5}{2})$ and $(\frac{-5}{2},).$

How do I know when the function isWhen the function is decreasing, I need help please. How do I know when it's a local maximum or local minimum?