Istill dont understand . what is the equation of the graphed line? 38 points

a graph with a line running through coordinates (-6, -3) and coordinates (6, -7)
enter your answer in slope-intercept form in the box.

click on image for better picture

First you need to find the slope with this formula y2 - y1/ x2-x1
(-6,-3)    (6, -7)
  x1,y1    x2, y2

now we substitute 
-7 - (-3) / 6 - (-6)    -4/12        the slope is -0.

now we need to plug it in in slope intercept form mx + b
m is the slope(0. and    b is the y-intercept  of the line(5)
the final answer will be - 0.33x + 5

                                                                       

Im pretty sure it would be 6 purple rectangles.

Any pictures or something i need more info