Use the "mixed partials" check to see if the following differential equation is exact.
If it is exact find a function F(x,y) whose differential, $dF(x,y)$ is the left hand side of the differential equation. That is, level curves $F(x,y) = C$ are solutions to the differential equation: $$( -3xy^2 + 1y )dx + ( -3x^2y +1x )dy= 0$$ First:
$M_y(x,y)=$ , and $N_x(x,y)=$ .

If the equation is not exact, enter not exact, otherwise enter in $F(x,y)$ here