We will write the equation in slope intercept form: y = mx + b where m=slope and b=y intercept..
Note the point (0,-5) is the y intercept.. we just need to fine the slope.
Note that since both points have a y coordinate of -5, we can assume this is a horizontal line that goes through -5 on the y axis... so our slope is 0 and the equation of the line is y = -5