Réponse :
bonjour
développer
(3x-1)²-25=
9x²-6x+1-25=
9x²-6x-24
(2x-1)²-(2x-1)(x+5)=
4x²-4x+1-2x²-10x+x+5=
2x²-13x+6
(5x-3)²-2(x-1)(5x-3)=
25x²-30x+9-2(5x²-3x-5x+3)=
25x²-30x+9-10x²+6x+10x-6=
15x²-14x+3
factoriser
(3x-1)²-25=
(3x-1)²-5²=
(3x-1-5)(3x-1+5)=
(3x-6)(3x+4)
(2x-1)²-(2x-1)(x+5)=
(2x-1)(2x-1)-(2x-1)(x+5)=
(2x-1)((2x-1)-(x+5))=
(2x-1)(2x-1-x-5)=
(2x-1)(x-6)
(5x-3)²-2(x-1)(5x-3)=
(5x-3)(5x-3)-2(x-1)(5x-3)=
(5x-3)((5x-3)-2(x-1)(5x-3)=
(5x-3)(5x-3-2x+2)=
(5x-3)(3x-1)
avecx=0 a(x)
(3×0-1)²-25=(-1)²-25=1-25=-24
x=-2
(3×(-2)-6)(3×(-2)+4)=
(-6-6)(-6+4)=
-12×(-2)=24
Explications étape par étape
