1) f(x) = x² - 8x + 16 + 2x² + 10x - 17 = 3x² + 2x - 1
(3x-1)(x+1) = 3x² - x + 3x - 1 = 3x² + 2x - 1 = f(x)
2) la forme developpee: 3x² + 2x - 1
la forme factorisee: (3x-1)(x+1)
3) a. forme developpee: f(0) = -1
b. forme factorisee: x = -1 ou x = 1/3
c. forme factorisee: f(-1) = 0
d. forme developpee: 3x²+2x = 0
x(3x+2) = 0
x = 0 ou x = -2/3
