1. On the coordinate plane, plot the set of points $L(x, y)$ that are solutions to the equation $\frac{x^{2}+x}{y^{2}+y}=1$.
1. The lines $y=x$ and $y=-x-1$ excluding the points with coordinates (0, 0), (0, -1), (-1, 0), (-1, -1), form the set of points as shown in the figure.