besoin daide svpp!!!! 20points

Réponse:

Bonsoir,

a= (4x-9)² --> IR2---> ( 4x)²-36x+9²= 16x²-72x+81

b= (3x+6)²--> IR1---> (9x)²+36x+6²= 81x²+36x+36

c= (2x+5)(2x-5)= IR3--> a²-b² = (2x)²-5² = 4x²-25

d= (-7x+8)²=(8-7x)²--> IR2---> 8²-112x+(7x)²

= 49x²-112x+64

A= -9x(-5x-7)-(8x²-2x+1)-->(45x²+63)-(8x²-2x+1)

= 37x²-2x+62

B= (7x+2)²-(4x-3)(2x+7) ---> IR1

B= (7x+2)²-(8x²+28x-6x-21)

B= ((7x)²+28x+2²)-(8x²+22x-21)

B= (49x²+28x+4)-(8x²+22x-21)

B= 41x²+6x+25

C= (4x-5)(4x+5)+(8+3x)(6x-1)

C= ((4x)²-5⁵)+ (48x-8+18x²-3x)

C= 16x²-25 + 45x -8 +18x²

C= 34x²+45x-33

D= -2(6x-3)(5-x)-(3x-4)²---> IR1

D= -2(30x-6x²-15+3x) -( (3x)²-24x+4²)

D= -2(-6x²+33x-15) - (9x²-24x+16)

D=( 12x²-66x+30) - (9x²-24x+16)

D= 3x²-42x+14

E= -7(-2x+9)-3(7-3x)(3x+7) --->IR3

E= (14x-63)- 3(7-3x)(7+3x)

E= (14x-63)- 3( 7²-(3x)²)

E= (14x-63)- 3(49-9x²)

E= (14x-63)- ( 147-27x²)

E= 27x²+14x-210

F= (8x+1)²-(7x-2)²--> IR1,IR2

F= ((8x)²+16x+1²)-((7x)²-28x+2²)

F= (64x²+16x+1) - ( 49x²-28x+4)

F= 15x²+44x-3

Ou

F= (8x+1)²-(7x-2)² -->IR3

F= ((8x+1)-(7x-2))((8x+1)+7x-2)

F= (x+3)(15x-1)

Bonne fin de soirée

Explications étape par étape:

IR1= identité remarquable 1:

(a+b)² <----> a²+2ab+b²

IR2= identité remarquable 2:

(a-b)² <------>a²-2ab+b²

IR3= identité remarquable 3:

(a+b)(a-b) <----->a²-b²