bonjour
( 3 x + 5) + ( x² + 6 ) = 3 x + 5 + x² + 6 = x² + 3 x + 11
( - 3 x + 5 ) - ( x² - 6 ) = - 3 x + 5 - x² + 6 = - x² - 3 x + 11
( 3 x + 5) - ( x² - 6 ) = 3 x + 5 - x² + 6 = - x² + 3 x + 11
- ( 3 x + 5) - ( x² - 6) = - 3 x - 5 - x² + 6 = - x² - 3 x + 1