Sagot :

maudmarine

Bonjour

a. (5x - 1) (x + 3) + (5x - 1)²

= 5x² + 15x - x - 3 + 25x² -10x + 1

= 30x² + 4x - 2

b.4 - 2x (3x -1) +2 (5x - 4)

= 4 - 6x² + 2x + 10x - 8

= - 6x² + 12x - 4

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

= 5x - 6x-3  +2x² -3x-10x+15

=2x²- 14x+12          

Teamce

Bonjour,

A= (5x-1)(x+3) + (5x-1)²

A= 5x² + 15x - x - 3 + (5x-1)²

→ identité remarquable :

  • (a-b)² = a² - 2ab + b²

A= 5x² + 14x - 3 + (5x)² - 2*5x*1 + 1²

A= 5x² + 14x - 3 + 25x² - 10x + 1

A= 30x² + 4x - 2

B= 4 - 2x(3x-1) + 2(5x-4)

B= 4 - (6x² - 2x) + 10x - 8

B= 4 - 6x² + 2x + 10x - 8

B= -6x² + 12x - 4

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

C= 5x - (6x + 3) + 2x² - 3x - 10x + 15

C= 5x - 6x - 3 + 2x² - 3x - 10x + 15

C= 2x² - 14x + 12

* = multiplication

Bonne journée.