Sagot :
bjr
A = (4 -x)² - 4 = (4 - x) (4 - x) - 4 = 16 - 4x - 4x + x² - 4 = x² - 8x + 12
et
A = (4-x)² - 2² = (4-x+2) (4-x-2) = (-x+6) (-x+2)
puisque a² - b² = (a+b) (a-b)
bjr
A = (4 -x)² - 4 = (4 - x) (4 - x) - 4 = 16 - 4x - 4x + x² - 4 = x² - 8x + 12
et
A = (4-x)² - 2² = (4-x+2) (4-x-2) = (-x+6) (-x+2)
puisque a² - b² = (a+b) (a-b)