SVP je n'arrive pas meri beaucoup c'est le 52

Exercice 52 : 

1) C = (2x - 3)² - (x - 2) (2x - 3)
C = (2x)² - 2 * 2x * 3 + 3² - [x * 2x + x * (- 3) - 2 * 2x - 2 * (- 3)]
C = 4x² - 12x + 9 - (2x² - 3x - 4x + 6)
C = 4x² - 12x + 9 - 2x² + 3x + 4x - 6
C = 2x² - 5x + 3

2) C = (2x - 3)² - (x - 2) (2x - 3)
C = (2x - 3) [(2x - 3) - (x - 2)]
C = (2x - 3) (2x - 3 - x + 2)
C = (2x - 3) (x - 1)

3) Pour x = 1

C = (2 * 1 - 3) (1 - 1)
C = (2 - 3) * 0
C = - 1 * 0
C = 0

1) C = (2x-3)² - (x-2)(2x-3)
C = (2x-3)(2x-3) - (x-2)(2x-3)
C = 2x*2x-2x*3-3*2x+3*3-x*2x-x*3-2*2x+2*3
C = 4x²-6x-6x+9-2x²-3x-4x+6
C = 4x²-2x²-6x-6x-3x-4x+9+6
C = 2x²-12x-3x-4x+15
C = 2x²-15x-4x+15
C = 2x²-19x+15

2) C = (2x-3)(2x-3) - (x-2)(2x-3)
C = (2x-3)[(2x-3) - (x-2)]
C = (2x-3)(2x-3-x+2)
C = (2x-3)(2x-x-3+2)
C = (2x-3)(x-1)
C = 2x*x-2x*1-3*x+3*1
C = 2x²-2x-3x+3
C = 2x²-5x+3

3) C pour x = 1
C = 2x²-5x+3
C = 2-5+3
C = -3+3
C = 0