Question

Paul says the slope of the line is zero

Phoebe says the slope of the line is undefined

A. Paul
B. Phoebe

Why did you use that answer?

Answer 1

B. Phoebe

Explanation:

Let's find the slope of the line that passes through (12, 5) and (12, 9).

Slope =
`(y_2 - y_1)/(x_2 - x_1) = (9 - 5)/(12 - 12) = (4)/(0)` = undefined.

14 can't be divided by zero. Therefore, it is concluded that the slope of the line is undefined.

Therefore, Phoebe is correct.