A= 5(2x-4)-3(-2x-5)
= 10x - 20 + 6x + 15
= 16x - 5
B= 4x(-3+4)+5x(7x-6)
= -12x + 16x + 35x² - 30x
= 35x² - 26x
C= 3-5x(-7x+5)-(-2x²-3x+8)
= 3 + 35x² - 25x + 2x² + 3x -8
= 37x² - 22x - 5
D= (3+2x)(5-3x)-(2-3x)(6x-5)
= 45 - 9x + 10x -6x² - 12x + 10 + 18x² - 15x
= 12x² - 26x + 55
En espérant t'avoir aidé.
