Question 151715
You are asked to find the equation of the line in the form {{{y = mx +b}}}
You are given the slope {{{m=-1/2}}} 
You are given a point that is not the y intercept (b).
So you need to find b. The point b is (0,b)
{{{m = (y[2]-y[1])/(x[2]-x[1])}}}
{{{-1/2 = (-6 - b)/(6 - 0)}}}
{{{-3 = -(6+b)}}}
{{{3 = 6 + b}}}
{{{-3 = b}}}

{{{y = (-1/2)x - 3}}}