Question

what is the slope of the line where equation is x=-8

Answer 1

0
It's just a straight line. No Slope :)

Answer 2

Where x=-8 is a vertical line. It has an undefined slope.

Answer 3

thanks for answering but how did you get that?

Answer 4

it is undefined.as the line is parallel to y axis.tan90=undefined.as shown by malevolence 19