Bonjour aider moi à faire cet exercice svp Merci

Réponse :

Explications étape par étape

a)

9x²-42x + 49

a²- 2ab + b²= (a-b)²

(3x)²-2*7*3x + (7)²

(3x)²-42x+(7)²

= ( 3x - 7)²

b)

4x²-9

a²-b²=(a-b)(a+b)

(2x)²-(3)²

= (2x-3)(2x+3)

c)

25x²+30x+9

a²+2ab+b²= (a+b)²

25x²+30x+9

= (5x)²+ 2*5x*3 + (3)²

= (5x+3)²

d)

(5x+1)(3-2x)- (5x+1)(2x+1)

= (5x+1) ( (3-2x) - (2x+1))

= (5x+1) ( 3 - 2x -2x -1)

= (5x+1)( - 4x +2)

e)

(x+1)(2x-1)-(2x-1)*1

= (2x-1) ( x+1-1)

= (2x-1)x

f)

(2x-1)²* + (2x-1)(3x+1)

= (2x-1)(2x-1)+(2x-1)(3x+1)

= (2x-1) ((2x-1)+(3x+1))

= (2x-1) (2x-1+3x+1)

= (2x-1) (5x)

= 5x(2x-1)