bonjour
2 ( x + 9/4 )² - 121 /8
= 2 ( x² + 18 x /4 + 81/16 ) - 121/8
= 2 x² + 36 x /4 + 162 /16 - 121/8
= 2 x² + 9 x + 162/16 - 242/16
= 2 x² + 9 x - 80/16
= 2 x² + 9 x - 5
