Vous pouvez m’aidez svp Merci d’avance

Explications:

1)

H=4x^2-81+(x-3)(2x+9)

H=4x^2-81+(2x^2+9x-6x-27)

H=4x^2+2X^2+9x+6x-81-27

H=6x^2+15x-108

2) a)

H=4x^2-81

H=4x^2-9^2

H=(2x+9)(2x-9)

b)

H=(2x+9)(2x-9)+(x-3)(2x+9)

3)

(2x+9)(3x-12)=0

6x^2-24x+27x-108

6x^2+3x-108

∆=b^2-4ac

∆=(3)^2-4(6)(-108)

∆=9+2592

∆=2601

√∆=√2601=51

X1=-b+√∆/2a

X1=-3+51/24=48/24=2

X2=-b-√∆/2a

X2=-3-51/24=-54/24=9/4

S={2;9/4}