(Solved): please help  Differentiate the function. Then find an equation of the tangent line at the indic ...

Differentiate the function. Then find an equation of the tangent line at the indicated point on the graph of the function. \[ w=g(z)=5+\sqrt{9-z}, \quad(z, w)=(8,6) \] The derivative of the function \( w=g(z)=5+\sqrt{9-z} \) is (Type an exact answer, using radicals as needed.) An equation of the tangent line is (Type an equation.)