Question 110709
You need the two-point form of the line to start.
:
{{{y-y[1]=((y[2]-y[1])/(x[2]-x[1]))(x-x[1])}}}
:
Then decide which of your points is number 1 and which is number 2.  It doesn't matter, but you need to be consistent when you plug the numbers into the form.
:
{{{y-(-6)=((-6-(-6))/(5-(-5)))(x-(-5))}}}
{{{y+6=(0/10)(x+5)}}}
{{{y=-6}}}
:
And you have a horizontal line through the point (0,-6)