Find equation of Tangent line at $(4, 1)$ on $5y^3 + x^2 = y + 5x$ Can someone help me find equation of tangent line at $(4, 1)$ on
 $5y^3 + x^2 = y + 5x$
$Y=f(x)$
I dont know how to isolate the $Y$

$$\dfrac{d}{dx}5y^3 + x^2 = y + 5x$$
$$=y'15y^2 + 2x = y' + 5$$
$$=y'15y^2-y' = -2x + 5$$
$$=y'(15y^2-1) = -2x + 5$$
$$=y' = \dfrac{-2x + 5}{(15y^2-1)}$$
Plugging in the point $(4,1)$ gives 
$$y'=-\dfrac{3}{14}$$
