EXN°6
A(x) = 16x² - 25
= (4x)² - 5²
identité remarquable a² - b² = (a + b)(a - b)
a = 4x
b = 5
A(x) = (4x + 5)(4x - 5)
B(x) = - 4x² - 12x
= -4x(x + 3)
C(t) = 49t² +56t + 16 = (7t + 4)²
Identité remarquable (a + b)² = a² + 2ab + b²
a = 7t
b = 4
2ab = 2(7t)(4) = 56t
D(x) = (3x -2)(5 - 2x) + 7(5 - 2x)
= (5 - 2x)[3x - 2 + 7)
= (5 - 2x)(3x + 5)
E(x) = 1 + 25x² - 10x
= 25x² + 10x + 1 = (5x + 1)²
Identité remarquable (a + b)² = a² + 2ab + b²
a = 5x
b = 1
2ab = 2(5x)1 = 10x
F(x) = (x + 1)² - (x - 3)² = (x + 1 + x - 3)(x + 1 - (x - 3) = 4(2x - 2)= 8(x - 1)
identité remarquable a² - b² = (a + b)(a - b)
a = x + 1
b = x - 3
G(x) = (2x + 7)² + (2x -7)(2x +7)
= (2x + 7)(2x + 7 + 2x - 7)
= (2x + 7)(4x)
= 4x(2x +7)
vous faite le reste de l'exo
