\(\left \{\begin{array}{rcr} x^{2} - y^{2} & \leq & 1 \\ x^{2} + 4y^{2} & \geq & 4 \end{array} \right .\)
\(\left \{\begin{array}{rcr} x^{2} + y^{2} & < & 25 \\ x^{2} + (y - 3)^{2} & \geq & 10 \end{array} \right .\)
\(\left \{\begin{array}{rcr} (x - 2)^{2} + y^{2} & < & 1 \\ x^{2} + 4y^{2} & < & 4 \end{array} \right .\)
\(\left \{\begin{array}{rcr} y & > & 10x - x^{2} \\ y & < & x^{3} + 8 \end{array} \right .\)
\(\left \{\begin{array}{rcr} x + 2y^{2} & > & 2 \\ x^{2} + 4y^{2} & \leq & 4 \end{array} \right .\)