Question 1151234
          Given that,
       

       ae=5------------1 (where a is the semimajor axis
                               e  is eccentricity       )


     and given 2a=12
            
               => a=6--------2
 
     -> put 2 in 1 ,you will get
          
             e=5/6

       squaring on both sides


         e^2=25/36             [we know that 

                                    e^2=1-b^2/a^2  where b=semi minoraxies]
      => 1-b^2/a^2=25/36   


      =>  1-b^2/36=25/36          (a=6 from 2)


      =>    36-b^2=25

      =>  b^2=11--------------3



we know that the standard equation  of ellipse looks like x^2/a^2+y^2/b^2=1

         we know a^2=36(from 2) and b^2 =11(from 3)


now the equation becomes x^2/36+y^2/11=1