Chapter 8.5A, Problem 11A

For each of the following, find the slope, if exists of the line determined by the given pair of points.

a. $\left(4,3\right)$ and $\left(-5,0\right)$

b. $\left(\sqrt{5},2\right)$ and $\left(1,2\right)$

c. $\left(a,a\right)$ and $\left(b,b\right)$

d. $\left(\sqrt{5},2\right)$ and $\left(\sqrt{5},-2\right)$