Question

Find the slope of the line that contains (9, -1) and (9, 9)

Answer 1

(9+1)/(9-9)

equals

zero.

Answer 2

means the line is is parallel to x-axis!

Answer 3

Using the slope formula:
\[slope = \frac{y_{2}-y_{1}}{x_{2}-x_{1}} = \frac{9+1}{9-9} = \frac{10}{0}\]
Your slope is undefined (not zero)

Answer 4

the line is vertical so its slope is UNDEFINED

Answer 5

its parallel to the y axis, not x axis

Answer 6

Yeah, its parellel to y-axis/./

My bad.

Answer 7

its undefined.