Réponses

2013-03-07T17:55:31+01:00

= x² + 2.x.4 + 4² - (x² +8x+ 2x + 16)

 

= x² + 8x + 16 - x² - 8x - 2x - 16

 

= - 2x

2013-03-07T17:56:00+01:00

 Dévelloper :
(x+4)²-(x+2)(x+8)
= (x² + 2*x*4+4²)-(x*x+x*8+x*x+x*2)
= (x²+8x+16)-(x²+8x+x²+2x)
=x²+8x+16-x²-8x-x²-2x
=-x²-2x+16