What is the slope of the line that passes through (2, 5) and (-1, 5) ?

(2,5) (-1,5) ... notice that ur y's are the same number ... they are both 5.

This means that u have a horizontal line which has a slope of 0. If the y's are the exact same number, then u have a horizontal line.

if the x's would have been the same number, then u would have had a vertical line with an undefined slope