Bonjour,
a) 3 (x - 3) + (x - 3) (3x - 1)
= (x - 3) (3x - 1 + 3)
= (x - 3) (3x + 2)
b) (2x + 5) (3x - 2) - (x - 2) (2x + 5)
= (2x + 5) [(3x - 2) - (x - 2)]
= (2x + 5) (3x - 2 - x + 2)
= 2x (2x + 5)
c) (4x - 4) (2x + 7) + (x - 1) (- 2x + 7)
= 4 (x - 1) (2x + 7) + (x - 1) (- 2x + 7)
= (x - 1) (6x + 35)
d) (1/3x + 1) (2x - 3) + (1/2x + 1) (4x - 6)
= 4 (2x - 3) (1/2x + 1) + (1/3x + 1) (2x - 3)
= 1/3 (2x - 3) (4x - 9)
