If (My-Nx)/N = Q, where Q is a function of x only, then the differential equation M + Ny' = 0 has an integrating factor of the form mu(x) = e^integral(Q(x) dx). Find an integrating factor and solve the given equation. (15x^2y + 2xy + 5y^3) dx + (x^2 + y^2) dy = 0. The integrating factor is mu(x) = . Do not enter an arbitrary constant. The solution in implicit form is = c, where c is a constant of integration.