Réponses

2013-04-11T19:17:10+02:00

C = (2x+3)² -49

C = (2x² +2*2x*3+3²) -49

C = 2x² +12x +9 -49

C = 2x² +12x -40

 

D = (2-x)² - (4x+5)²

D = (2² -2*2*x+x²) - (4x² +2*4x*5 +5²)

D = 4-4x+x²-16x+40x+25

D = x²+20x+29

 

E = 25- (3x-1)²

E = 25- (3x² -2*3x*1+1²)

E = 25- 9x -6x +1

E = (-15x)+25

 

F = (4x +1)² - (7-2x)²

F = (4x² +2*4x*1+1²) - (7² -2*7*2x+2x²)

F = 16x +8x +1-49-98x +4x²

F = 4x² -74x -48