need this answer please

First of all, let's find the slope of the line:
[tex] m = \dfrac{\Delta y}{\Delta x} = \dfrac{A_y-B_y}{A_x-B_x} = \dfrac{6-6}{5+3} = 0 [/tex]
The line has zero slope. In fact both points share the same y coordinate, which means that this is a horizontal line. As such, all points on the line will have the same y coordinate, which also identifies the equation of the line:
[tex] y = 6 [/tex]