Hej!
[tex]x^3+7x^2+12x=0\\\\x(x^2+7x+12)=0\\\\x=0 \ \vee \ x^2+7x+12=0\\\\a=1, \ b=7,\ c=12\\\\\Delta=7^2-4\cdot1\cdot12=49-48=1\\\\\sqrt{\Delta}=\sqrt1=1\\\\x=\frac{-7-1}{2}=-4\\\\x=\frac{-7+1}{2}=-3\\\\x=\{-4;-3;0\}\\\\\text{Odp.A}[/tex]
