Réponses

2014-06-09T22:03:53+02:00
A= (-2x -6) (5x+4)
A = - 10x
² - 30x - 8x - 24
A = - 10x
² - 38x - 24

B= 4(2x-5)+(7x-1)
²
B = 8x - 20 + 49x
² - 14x + 1
B = 49x
² - 6x - 19

C= (3x-1)(3x+1)-(x-1)(8+2x)
C = (9x
² - 1) - (8x - 8 + 2x² - 2x)
C = 9x
² - 1 - 8x + 8 - 2x² + 2x
C = 7x
² - 6x + 7