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
