Réponse :

Explications étape par étape

Ex1

A=(5x-4)²= 25x²- 40x + 16

B=(2x-3)(2x+3)= 4x²- 9

C= (7x+6)(7x-5)= 49x²-35x+42x-30=49x²+7x-30

D= (5x+9)²= 25x²+90x+81

E=(10x+7)(10x-7)= 100x²-49

Ex2

F=(5x+2)²+(x-4)(5x+2)= (5x+2)((5x+2)+(x-4))=(5x+2)(6x-2)

G=(4x+7)²-(5x-3)(4x+7)= (4x+7)((4x+7)-(5x-3))=(4x+7)(4x+7-5x+3)=(4x+7)(-x+10)

H=16-9x²=4²-(3x)²= (4-3x)(4+3x)

I= (2x+5)²-(x+7)²= (2x+5+x+7)(2x+5-x-7)=(3x+12)(x-2)

J= (10x-5)²-(3x-1)²=(10x-5+3x-1)(10x-5-3x+1)=(13x-6)(7x-4)