[tex]x^3+y^3=3axy[/tex]
[tex]\dfrac{\mathrm d}{\mathrm dx}\left[x^3+y^3\right]=\dfrac{\mathrm d}{\mathrm dx}[3axy][/tex]
[tex]3x^2+3y^2\dfrac{\mathrm dy}{\mathrm dx}=3a\left(y+x\dfrac{\mathrm dy}{\mathrm dx}\right)[/tex]
[tex]\left(3y^2-3ax\right)\dfrac{\mathrm dy}{\mathrm dx}=3ay-3x^2[/tex]
[tex]\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{3ay-3x^2}{3y^2-3ax}[/tex]
[tex]\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{ay-x^2}{y^2-ax}[/tex]
