bonsoir
A(x) = ( 2 x - 3)² - ( 2 x - 3) ( x + 1)
A(x) = 4 x² - 12 x + 9 - ( 2 x² + 2 x - 3 x - 3)
A(x) = 4 x² - 12 x + 9 - 2 x² - 2 x + 3 x + 3
a(x) = 2 x² - 11 x + 12
A(x) = ( 2 x - 3) ( 2 x - 3 - x - 1) = ( 2 x - 3) ( x - 4)
A(0) = - 3 * - 4 = 12
A( - 2) = ( - 4 - 3) ( - 2 - 4) = - 7 * - 6 = 42
A( 4) = ( 8 - 3) ( 4 - 4) = 0
( 2 x - 3) ( x - 4) = 0
A = 0 pour x = 3/2 et 4