Bonsoir
Factoriser :
(x - 1)(2x + 5) + 4x^2 + 20x + 25
= (x - 1)(2x + 5) + (2x)^2 + 2 * 2x * 5 + 5^2
= (x - 1)(2x + 5) + (2x + 5)^2
= (2x + 5)(x - 1 + 2x + 5)
= (2x + 5)(3x + 4)
9x^2 - 81 - 2x(3x - 9)
= (3x)^2 - 9^2 - 2x(3x - 9)
= (3x - 9)(3x + 9) - 2x * 3(x - 3)
= 3(x - 3)(3x + 9) - 6x(x - 3)
= 3(x - 3)(3x + 9 - 2x)
= 3(x - 3)(x + 9)
5x - 20 - (2x + 3)(x - 4)
= 5(x - 4) - (2x + 3)(x - 4)
= (x - 4)(5 - 2x - 3)
= (x - 4)(-2x + 2)
= (x - 4) * 2(-x + 1)
= 2(x - 4)(-x + 1)
x(2x + 1) - 6x - 3
= x(2x + 1) - 3(2x + 1)
= (2x + 1)(x - 3)
(2t - 1)(t - 7) - t + 7
= (2t - 1)(t - 7) - (t - 7)
= (t - 7)(2t - 1 - 1)
= (t - 7)(2t - 2)
= (t - 7) * 2(t - 1)
= 2(t - 7)(t - 1)
(6x - 5)^2 + 12x - 10
= (6x - 5)^2 + 2(6x - 5)
= (6x - 5)(6x - 5 + 2)
= (6x - 5)(6x - 3)
= (6x - 5) * 3(2x - 1)
= 3(6x - 5)(2x - 1)
(3z - 5)^3 - 2z(3z - 5)^2
= (3z - 5)^2(3z - 5 - 2z)
= (3z - 5)^2(z - 5)
(4x + 3)(x - 1) + 2x^2 - 2
= (4x + 3)(x - 1) + 2(x^2 - 1)
= (x - 1)(4x + 3 + 2)
= (x - 1)(4x + 5)
