\[ 4 y(x)^2 y^{(3)}(x)+15 y'(x)^3-18 y(x) y'(x) y''(x)=0 \] ✗ Mathematica : cpu = 0.0729604 (sec), leaf count = 0 , could not solve
DSolve[15*Derivative[1][y][x]^3 - 18*y[x]*Derivative[1][y][x]*Derivative[2][y][x] + 4*y[x]^2*Derivative[3][y][x] == 0, y[x], x]
✓ Maple : cpu = 0.302 (sec), leaf count = 26
\[ \left \{ y \left ( x \right ) ={\frac {{\it \_C3}}{ \left ( -{{\it \_C2}}^{2}-2\,{\it \_C2}\,x-{x}^{2}+4\,{\it \_C1} \right ) ^{2}}} \right \} \]