Bonsoir,
4x² 9 -> Forme a²-b² = (a-b)(a+b)
[tex]4x^2-9=(2x-3)(x+1)\\
(2x-3)(2x+3)=(2x-3)(x+1)\\
(2x-3)(2x+3)=(2x-3)(x+1) = 0\\
(2x-3)(2x+3-(x+1))=0\\
(2x-3)(2x+3-x-1)=0\\(2x-3)(x+2)=0\\ [/tex]
2x-3= 0 ou x+2 = 0
[tex]\\
2x-3=0\\
x=\boxed{\frac{3}{2}}\\
\\
x+2=0\\
x=\boxed{-2}\\
\\
\\ S=\boxed{{-2;\frac{3}{2}}}[/tex]
