Question

What's the slope of 4, 1 and -9, 1

Answer 1

The slope is 0. (1-1)/(-9-4)= 0. 

Answer 2

slope = y2 - y1/ x2 - x1

1 - 1/-9 - 4
=0/-13

slope = 0 (meaning that this is the slope of a horizontal line.)

hope this helps :)