I'll make up a line shown below, since you didn't give one.
Your problem will be done the same way:

Let's say you were given this graph:



We take two points on the given line and find its slope:

Slope formula:



where (x1,y1) = (-2,2)
and where (x2,y2) = (10,-4)









That's the slope of the given line. A line perpendicular
to a given line has a slope which is the reciprocal of
the given line with the opposite sign.

The reciprocal of  with the opposite sign is ,
which is just 2.

Next we use the point-slope formula:
y - y1 = m(x - x1)
where (x1,y1) = (6,-7), and m = 2.




   <---answer

Now use the above as a model to solve yours. 
Here's the graph of the answer (in green): 




Edwin