Factoriser les expressions suivantes :
a. D(x) = 2x(x + 1) + (x − 2)(x+1);
= ( x + 1 ) ( 2 x + x - 2)
= ( x + 1 ) ( 3 x - 2 )
b. E(x) = (3x - 1)²-5(3x - 1);
= ( 3 x - 1 ) ( 3 x - 1 - 5 )
= ( 3 x - 1 ) ( 3 x - 6 )
c. F(x) = x² + 8x +16 - (2x+3)(x+4).
= ( x + 4 )² - ( 2 x + 3 ) ( x + 4)
= ( x + 4 ) ( x + 4 - 2 x - 3 )
= ( x + 4 ) ( - x + 1 )