-x=4-2y => x=2y-4 => x=2y-4 => x=2y-4 => x=2*11-4 => x=18
7x-3y=5 => 7(2y-4)-3y=5 => 14y-28-3y=5 => 11y=33 => y=11 =>y=11
-x=4-2y => x=2y-4 => x=2y-4 => x=2y-4 => x=2*11-4 => x=18
7x-3y=5 => 7(2y-4)-3y=5 => 14y-28-3y=5 => 11y=33 => y=11 =>y=11