5 x ( x + 2 ) - ( x + 2 )² = ( x + 2 ) ( 5 x - x - 2 ) = ( x + 2 ) ( 4 x - 2 )
= ( a - 1 )² ( 2 a + b - b ) =
= ( a - 1 )² × 2 a
_______________
= ( x + 1 )² + 3 ( x + 1 ) =
= ( x + 1 ) ( x + 1 + 3 ) =
= ( x + 1 ) ( x + 4 )
________________
= ( x³ + 1 ) ( 2 x³ - x³ + 1 ) =
___________________
h)
= ( x² + x + 1 )² - ( x² + x + 1 ) =
= ( x² + x + 1 ) ( x² + x + 1 - 1 ) =
= ( x² + x + 1 ) ( x² + x )