Implicit differentiation
posted by Alex .
implicit differentiation of x^3y^25x^2y+x=1

what is...
3x^2y^2 dx+2x^3ydy10xydx5x^2dy+dx=0
gather terms...
dx(3x^2y^210xy+1)+dy(2x^3y5x^2)=0
check this, easy to make a typo 
3x^2 y^2 + 2x^3 y y'  10xy  5x^2 y' + 1 = 0
y'(2x^3y  5x^2) = (3x^2y^2  10xy + 1)
y' = (10xy  3x^2y^2  1)/(2x^3y  5x^2)