Bonjour,
(2x + 1) - (2x + 1)² =
2x + 1 - (2x * 2x + 2x * 2 * 1 + 1²) =
2x + 1 - (4x² + 4x + 1) =
2x + 1 - 4x² - 4x - 1 =
- 4x² - 2x.
bonjour
[tex]( 2 x + 1 ) - ( 2 x + 1 )^{2} \\= 2 x + 1 - ( 4 x^{2} {+ 4 x + 1 )\\} \\= 2 x + 1 - 4 x ^{2} - 4 x - 1 \\\\= - 4 x^{2} - 2 x \\\\[/tex]