Math Problem help!!!!!!!!!!!!!

1) Find the slope of the tangent line to the curve: 2xy + 4y^3 = -570 at point(7, -5)

2) Fin the slope of the tangent line to the curve: 2((x^2)+(y^2))^2 = 25((x^2)-(y^2)) at point (3,1)

1) You have to use implicit differentiation:

2xy' + 2y + 12y^2 * y' = 0

y'[2x + 12y^2] = -2y

y' = -2y / [2x + 12y^2]

Now plug in (7,-5):

y' = -2(-5) / [2(7) + 12(-5)^2]

= 10/[14 + 300

= 10/314

= 5/157