\left \{ {{2y^2=36-x^2} \atop {2x^2=16}} \right. => \left \{ {{2y^2=24} \atop {x^2=8}} \right. => \left \{ {{x=\pm \sqrt{8} } \atop {y=\pm2 \sqrt{3} }} " alt=" \left \{ {{2y^2=36-x^2} \atop {3x^2-36-x^2=-20} \right.=> \left \{ {{2y^2=36-x^2} \atop {2x^2=16}} \right. => \left \{ {{2y^2=24} \atop {x^2=8}} \right. => \left \{ {{x=\pm \sqrt{8} } \atop {y=\pm2 \sqrt{3} }} " align="absmiddle" class="latex-formula">