développer et ordonner les expressions suivantes
a) - 3(x+1)(x-2) = - 3(x² - 2 x + x - 2) = - 3(x² - x - 2) = - 3 x² + x + 2
b) 2(x + 1)²- 5 = 2(x² + 2 x + 1) - 5 = 2 x² + 4 x + 2 - 5 = 2 x² + 4 x - 3
c) 3((x-1)²+2) = 3((x² - 2 x + 1 +2) = 3(x² - 2 x + 3) = 3 x² - 6 x + 9