Hi... You want to start out by having your two slopes:
(1,-1) (-3,-2), then you find the slope..
[tex] \frac{ - 1 + + 2}{1 - 3} = - \frac{1}{2} [/tex]
and then you should get the final answer:
[tex]y + 1 = - \frac{1}{2}(x - 1)[/tex]
I hope this is what you were looking for, I'm doing almost the same thing right now!