Points $A$ and $B$ have the same $y$-coordinate of 13, but different $x$-coordinates. What is the sum of the slope and the $y$-intercept of

Let A  =  (m, 13)      Let B  =  (n, 13)

Since the y coordinates are the same, the slope   = 0  and the y intercept  = 13

So...... the sum of the slope and y intercept is just 13