Use implicit differentiation where LaTeX:  \displaystyle y is a function of LaTeX:  \displaystyle x to find the derivative of LaTeX:  \displaystyle 8 \sqrt{5} x \sqrt{y} + 9 e^{x^{3}} e^{y^{3}}=-50

Taking the derivative of both sides using implicit differentiation gives: LaTeX:   27 x^{2} e^{x^{3}} e^{y^{3}} + \frac{4 \sqrt{5} x y'}{\sqrt{y}} + 8 \sqrt{5} \sqrt{y} + 27 y^{2} y' e^{x^{3}} e^{y^{3}} = 0  Solving for LaTeX:  \displaystyle y' gives LaTeX:  \displaystyle y' = - \frac{27 x^{2} \sqrt{y} e^{x^{3} + y^{3}} + 8 \sqrt{5} y}{4 \sqrt{5} x + 27 y^{\frac{5}{2}} e^{x^{3} + y^{3}}}