\[y = \frac{3x^{2} + 4x}{x} - \frac{x^{2} - 1}{x + 1} =\]
\[= \frac{x(3x + 4)}{x} - \frac{(x - 1)(x + 1)}{x + 1} =\]
\[= 3x + 4 - (x - 1) = 3x + 4 - x + 1 =\]
\[= 2x + 5;\ \ \ \ \ x eq 0,\ x eq - 1.\]