[tex] \left \{ {{7x-3y=24\ |\cdot-3} \atop {3x-7y=-16\ |\cdot7}} \right. \\\\ \left \{ {{-21x+9y=-72} \atop {21x-49y=-112}} \right. \\+-------\\\\-40y=-184\ \ \ \ |:-40\\x=4.6\\\\3\cdot4.6-7y=-16\\13.8-7y=-16\\-7y=-16-13.8\\-7y=-29.8\ \ \ \ \ |:-7\\y=4.257[/tex]