\[y = \frac{x^{3} + x^{4}}{x + x^{2}}\]
\[y = \frac{x³(x + 1)}{x(1 + x)}\]
\[x + x^{2} eq 0\]
\[x(1 + x) eq 0\]
\[x eq 0;\ \ x eq - 1\]
\[y = x^{2}\]