Suppose 4y + xy = 2. Evaluate d^2y/dx^2 at the point (-3, 2).
4y + xy = 2
4y' + y + xy' = 0
y' = -y/(x+4)
Now you can use the quotient rule or another implicit differentiation.
4y" + y' + y'^2 + xy" = 0
So, now just plug in (-3,2) to evaluate it there.