Question

how do i find at least one set of values for x and y so that the slope of the line through (5,8) and (x,y) is 0?

Answer 1

A(5,8) and B(x ,y)

m = (y₂ - y₁)/(x₂-x₁)

m = (y-8)/(x-5)
m = 0 if and only if y = 8
The equation becomes:
y = 0.x + b
8 = 0.x +b → y = 8 (line // to x-axis at y=8)