$ ( n2 + 5 ) . ( 2n2 - 32 ) $ ≤ $0 $
Vậy : $( n2 + 5 ) . ( 2n2 - 32 ) = 0 $
$=> ( n2 + 5 ) = 0$ hoặc $( 2n2 - 32 ) = 0$
$( n2 + 5 ) = 0$
$-> n2 = 0 - 5 = ( -5 )$
Vậy :$ x = ( - 2,5 )$
$ ( 2n2 - 32 ) = 0$
$-> 2n2 = 0 - 32 = ( - 32 )$
$-> 2n = ( -16 )$
$ -> x = -8$