Bonjour
1)Développer et réduire les expressions:
•A = 5(2x – 12)
A = 10x - 60
•D = (4t - 1)(4t + 1) - 2(t + 4).
D = 16t² - 1 - 2t - 8
D = 16t² - 2t - 9
•E = (x – 4)(3x + 1) – (4 - 5x)(2x + 3).
E = 3x² + x - 12x - 4 - (8x + 12 - 10x² - 15x)
E = 3x² + x - 12x - 4 - 8x - 12 + 10x² + 15x
E = 3x² + 10x² + x + 15x - 12x - 8x - 4 - 12
E = 13x² - 4x - 16
•-2(4 + 7x).
= - 8 - 14x
•2x(5x - 3) - 4(x + 1).
= 10x² - 6x - 4x - 4
= 10x² - 10x - 4
•3(5 - x)(5 + x).
= 3 (25 - x²)
= 75 - 3x²
•2(x - 5) + 3x + 7
= 2x - 10 + 3x + 7
= 5x - 3
2)Factoriser les expressions:
•B =64x² - 9.
B = (8x - 3) (8x + 3)
•C = (x + 1) - x(x + 1).
C = - (x - 1) (x + 1)
•3x² - x = x (3x - 1)
•5(x + 1) + (x + 1)²
= (x + 1) (x + 1 + 5)
= (x + 1) (x + 6)
•8x² + 4x - 2x = 8x² + 2x = 2x (4x + 1).
Réponse:
1)
[tex]10x - 60[/tex]
[tex]16t {}^{2} - 2t - 9[/tex]
[tex]13 {x}^{2} - 4x - 16[/tex]
[tex] - 8 - 14x[/tex]
[tex]10 {x}^{2} - 10x - 1[/tex]
[tex]75 - 3 {x}^{2} [/tex]
[tex]5x - 3[/tex]
2)
[tex]a {}^{2} - b {}^{2} = (a + b)(a - b) \:ici \: a = 8x \: et \: b = 3 \: donc \: (8x + 3)(8x - 3)[/tex]
[tex](1 + x)(1 - x)[/tex]
[tex]x(3x - 1)[/tex]
[tex]7(x + 1)[/tex]
[tex]2x(4x + 1)[/tex]
