What is the equation of this graphed line?

y+3 = (-1/3)(x+6) or y = (-1/3)x - 5

Step-by-step explanation:

First, find the slope of the line.  As we travel from (-6,-3) to (6,-7), x increases by 12 and y decreases by 4.  Thus, the slope, m, is m = rise/run = -4/12 = -1/3.  Using the point-slope formula to come up with an equation for this line:

y-[-3] = (-1/3)(x-[-6]), or y+3 = (-1/3)(x+6).

Alternatively, we could write this equation in slope-intercept form:

y = -3 - (1/3)x - 2, or y = (-1/3)x - 5