bonsoir. pouvez vous me donner ces calculs: 1.(3x+5) (9-6x) +3x+5 2.(9-5x)au carré - (4x+7) au carré 3.(7x-2) au carré - (7x-2)(7+5x) merc

Bonjour Ferrariornella

Factoriser et développer : 

[tex]1)\ (3x+5) (9-6x) +3x+5=(3x+5) (9-6x) +1(3x+5)\\(3x+5) (9-6x) +3x+5=(3x+5)[ (9-6x) +1]\\(3x+5) (9-6x) +3x+5=(3x+5)(9-6x +1)\\\\\boxed{(3x+5) (9-6x) +3x+5=-2(3x+5)(3x-5)}\\\\(3x+5) (9-6x) +3x+5=-2[(3x)^2-5^2]\\\\\boxed{(3x+5) (9-6x) +3x+5=-2(9x^2-25)}[/tex]


[tex]2)\ (9-5x)^2-(4x+7)^2=[(9-5x)+(4x+7)][(9-5x)-(4x+7)]\\9-5x)^2-(4x+7)^2=(9-5x+4x+7)(9-5x-4x-7)\\\boxed{9-5x)^2-(4x+7)^2=(16-x)(2-9x)}\\\\(9-5x)^2-(4x+7)^2=32-144x-2x+9x^2\\\\\boxed{(9-5x)^2-(4x+7)^2=9x^2-146x+32}[/tex]


[tex]3)\ (7x-2)^2-(7x-2)(7+5x)=(7x-2)(7x-2)-(7x-2)(7+5x)\\(7x-2)^2-(7x-2)(7+5x)=(7x-2)[(7x-2)-(7+5x)]\\(7x-2)^2-(7x-2)(7+5x)=(7x-2)(7x-2-7-5x)\\\\\boxed{(7x-2)^2-(7x-2)(7+5x)=(7x-2)(2x-9)}\\\\\\(7x-2)^2-(7x-2)(7+5x)=14x^2-63x-4x+18\\\\\boxed{(7x-2)^2-(7x-2)(7+5x)=14x^2-67x+18}[/tex]