\[ -y(x) f''(x)+f'(x) y'(x)+f(x) y(x)^3+y(x) y''(x)-y'(x)^2-y(x)^4=0 \] ✗ Mathematica : cpu = 0.473411 (sec), leaf count = 0 , could not solve
DSolve[f[x]*y[x]^3 - y[x]^4 + Derivative[1][f][x]*Derivative[1][y][x] - Derivative[1][y][x]^2 - y[x]*Derivative[2][f][x] + y[x]*Derivative[2][y][x] == 0, y[x], x]
✗ Maple : cpu = 0. (sec), leaf count = 0 , could not solve
dsolve(diff(diff(y(x),x),x)*y(x)-diff(y(x),x)^2+diff(f(x),x)*diff(y(x),x)-diff(diff(f(x),x),x)*y(x)+f(x)*y(x)^3-y(x)^4=0,y(x))