bonjour
A = 2 x² - 5 x ³
A = 2 ( 1)² - 5 ( 1 )³ = 2 - 5 = - 3
A = 2 ( - 1 )² - 5 ( - 1 ) ³ = 2 + 5 = 7
A = 0
A = 2 ( - 3 )² - 5 ( - 3 ) ³ = 18 + 135 = 153
