Réponse:

Bonsoir j'espère que vous allez bien ;)

a) (2x -3) (5x + 1) + (4x -2 )²

= 2x × 5x + 2x × 1 + (-3) × 5x + (-3) × 1 + ( 4x - 2 )²

= 10x² + 2x - 15x - 3 + 16x - 16x² + 4

= 26x² -29x + 1

b) (2x -5)² - (-x + 4 )²

= 4x² -20x + 25 - x² - 8x + 16

= 3x² -12x + 9

c) 3( 4x -2)² -2 (-x + 3)²

= 3( 16x² - 16x + 4 ) -2 ( x² -12x + 9 )

= 48x² - 48x + 12 -2x² + 24x - 18

= 46x² -36x -6

Réponse :

a) (2x - 3)(5x + 1) + (4x - 2)^2                    ((a - b)^2 = a^2 + b^2 - 2ab)

= (10x^2 - 13x -3) + (16x^2 - 16x + 4)

= 26x^2 - 29x + 1

_____

b) (2x - 5)^2 - (4 - x)^2

= 4x^2 - 20x + 25 - x^2 - 16 + 8x

= 3x^2 - 12x + 9

_____

c) 3(4x - 2)^2 - 2(3 - x)^2

= 3(16x^2 - 16x + 4) - 2(x^2 - 6x + 9)

= 48x^2 - 48x + 12 - 2x^2 + 12x - 18

= 46x^2 - 36x - 6