I'm feeling pretty stupid right now because I can't remember how to do these.

if f(x) = (2x-5)/(x^2-4), write an equation of the tangent line to f at point x=0. *How do I find the slope of the tangent line?

and how do you put x=ln4 into a y= equation?

Take the derivative of f(x), that is the slope.

The second question if y is a function of x, then put in ln4 for the value of x to be determined.