Réponse :
Bonjour,
[tex]C = (7x + 2)(5x - 4) - 3(7x + 2)\\\\= (7x + 2)[(5x - 4) - 3]\\\\= (7x + 2)(5x - 4 - 3)\\\\= (7x + 2)(5x - 7)[/tex]
[tex]D = (2x - 1)^2 - (3x + 2)^2\\\\= [(2x - 1) - (3x + 2)][(2x - 1) + (3x + 2)]\\\\= (2x - 1 - 3x - 2)(2x - 1 + 3x + 2)\\\\= (-x - 3)(5x + 1)[/tex]
[tex]E = x^2 - 25 + 7(x + 5)^2\\\\= (x^2 - 5^2) + 7(x + 5)^2\\\\= (x - 5)(x + 5) + 7(x + 5)(x + 5)\\\\= (x + 5)[(x - 5) + 7(x+5)]\\\\= (x + 5)(x - 5 + 7x + 35)\\\\= (x + 5)(8x + 30)\\\\= 2(x + 5)(4x + 15)[/tex]
[tex]F = 7(8x - 10) + (4x - 5)\\\\= 14(4x - 5) + (4x - 5)\\\\= (4x - 5)(14 + 1)\\\\= 15(4x - 5)[/tex]
