Use implicit differentiation where LaTeX:  \displaystyle y is a function of LaTeX:  \displaystyle x to find the derivative of LaTeX:  \displaystyle 5 \sqrt{7} \sqrt{y} e^{x^{2}} + 3 e^{y^{2}} \sin{\left(x^{3} \right)}=30

Taking the derivative of both sides using implicit differentiation gives: LaTeX:   9 x^{2} e^{y^{2}} \cos{\left(x^{3} \right)} + 10 \sqrt{7} x \sqrt{y} e^{x^{2}} + 6 y y' e^{y^{2}} \sin{\left(x^{3} \right)} + \frac{5 \sqrt{7} y' e^{x^{2}}}{2 \sqrt{y}} = 0  Solving for LaTeX:  \displaystyle y' gives LaTeX:  \displaystyle y' = - \frac{2 x \left(9 x \sqrt{y} e^{y^{2}} \cos{\left(x^{3} \right)} + 10 \sqrt{7} y e^{x^{2}}\right)}{12 y^{\frac{3}{2}} e^{y^{2}} \sin{\left(x^{3} \right)} + 5 \sqrt{7} e^{x^{2}}}