\[ 8 y''(x)+9 y'(x)^4=0 \] ✓ Mathematica : cpu = 0.0305166 (sec), leaf count = 90
\[\left \{\left \{y(x)\to c_2-\frac {1}{3} \sqrt [3]{-\frac {1}{3}} \left (9 x-8 c_1\right ){}^{2/3}\right \},\left \{y(x)\to \frac {\left (9 x-8 c_1\right ){}^{2/3}}{3 \sqrt [3]{3}}+c_2\right \},\left \{y(x)\to \frac {1}{9} \left ((-3)^{2/3} \left (9 x-8 c_1\right ){}^{2/3}+9 c_2\right )\right \}\right \}\]
✓ Maple : cpu = 0.089 (sec), leaf count = 51
\[ \left \{ y \left ( x \right ) = \left ( x+{\it \_C1} \right ) ^{{\frac {2}{3}}}+{\it \_C2},y \left ( x \right ) ={\frac {i\sqrt {3}-1}{2} \left ( x+{\it \_C1} \right ) ^{{\frac {2}{3}}}}+{\it \_C2},y \left ( x \right ) =-{\frac {i\sqrt {3}+1}{2} \left ( x+{\it \_C1} \right ) ^{{\frac {2}{3}}}}+{\it \_C2} \right \} \]