'Guest' directions were correct..... try them to find your answer....
I got 11=20+-9 and it was incorrect
Find the slope which is m. (I think you know how)
(-17 -11) / (-2-5) = slope = m = 4
Then plug m in the equation y = mx + b.
y = 4 x + b
Then plug in one of the points to find b.
11 = 4 (5) + b
b = -9
y = 4x-9