bonjour
B(x) = (3x – 4)^2 -(x+6)^2
B (x) = 9 x² - 24 x + 16 - ( x² + 12 x + 36 )
B (x) = 9 x² - 24 x + 16 - x² - 12 x - 36
B (x) = 8 x² - 36 x - 20
B = ( 3 x - 4 + x + 6 ) ( 3 x - 4 - x - 6 )
B (x) = ( 4 x + 2 ) ( 2 x - 10 )
B (x) = 2 ( 4 x +2 ) ( x - 5 )
b (x) = 0
soit x = - 2 , soit x = 5
B (x) = - 20
8 x² - 36 x - 20 = - 20
8 x² - 36 x - 20 + 20 = 0
8 x² - 36 x = 0
4 x ( 2 x - 9 ) = 0
x = 0 ou 9/2
