Answer:
Slope = 0
Equation:

Explanation:
Note that the diagonal AB is a horizontal line parallel to the x axis. The Slope m of a line is a measure of how the function f(x) changes when x increases or decreases.
Note, however, that horizontal lines such as segment AB do not change and their value of y does not depend on the value of x. Therefore all horizontal lines have slope m = 0.
Finally, the equation of line AB is
