Write an equation of the hyperbola that meet each set of conditions

37. A vertex is at (4,5) the center at (4,2) and an equation of one asymptote is 4y+4=3x

I managed to get this far into writing the equation (y-2)^2/9+(x-4)^2/ but I am not sure how to get "b" in the equation.

2. The hyperbola as foci at (0,8) and (0,-8) and eccentricity is 4/3

I am not sure how to do this one