Question

Find the slope of the line through the pair of points a (2,-3) p(2,9)

Answer 1

(x₁,y₁) = (2,-3)
(x₂,y₂) = (2,9)

To determine the slope using two points lie on the line, we could use the following formula
m = $\dfrac{y_{2}-y_{1}}{x_{2}-x_{1}}$

plug in the numbers
m = $\dfrac{9-(-3)}{2-2}$
m = $\dfrac{9+3}{0}$
m = $\dfrac{12}{0}$
m = undefined

The slope is undefined, the line is vertical