Proof :

          let  a =1 and  b = 1   then ,

          a = b        

          a ²   =  a *  b

           a ² -  b² =  ab - b²                        ,Take Common Factor (بأخذ العامل المشترك )

           ( a + b )( a - b) = b ( a - b )         ,Dividing By  (a - b )

            ( a + b )    =  b                              ,But   a=1 and  b=1    then

                2 = 1         #

End Of Proof .

The Problem Is We Can Not Divide By    ( a - b )  Because It Is Equal To Zero .. :))

( a - b ) = 0 , So We Can't Dividing By It .