Question 125495
The essential characteristic of a horizontal line is that the y-coordinates of every point on the line are equal, and the x-coordinates are the set of all real numbers.


In order for the line to pass through the point (-2,-3), every point on the line must have a y coordinate of -3.  So the equation is simply {{{y=-3}}}.


Another way to look at it is that a horizontal line has a slope of zero, so using the point-slope form of the straight line:  {{{y-y[1]=m(x-x[1])}}}, you get:


{{{y-(-3)=0(x-(-2))}}}


{{{y+3=0}}}


{{{y=-3}}}.