a. Développe puis réduis les expressions.A = (4x – 1)(3x + 5) – (x – 7) B = (x + 5)(2x – 5) – (3x2– 7x + 5)

A = (4x – 1)(3x + 5) – (x – 7) = 12 x² + 20x - 3x -5x - x +7
 = 12x² + 11x +27B = (x + 5)(2x – 5) – (3x2– 7x + 5)=2x² - 5x + 10x -25 - (6 -7x+5)
= 2x² +5x -25 -6+7x-5
= 2x²+ 12x-36

A= (12x^2 + 20x - 3x - 5) - (x- 7)
  = 12x^2 + 17x - 5 - x + 7
 = 12x^2 + 16x +2

B= (2x^2 - 5x + 10x - 25) - (3x^2 - 7x + 5)
  = 2x^2 - 5x + 10x - 25 - 3x^2 + 7x - 5
 = -x^2+ 12x - 30
=- (x^2- 12x + 30)