Determine the exact equations of the tangents to the curve which pass through point P

curve = (8-x)^(1/2)

point = 5,2

I'd like to see how you would solve this. What I tried to do is set the variables of the point as: a, (8-a^(1/2))

and the slope would be

-1 /( 2(8-x)^(1/2) )

Is this right? Putting this into the y-y0 = m (x-x0) seems to get messy...