[tex] Discriminant= b^{2}-4.a.c \\ \\ We\:need\:to:-b+ \sqrt{discriminant} /2a \\ \\ 9x^{2} +12x+4=0 \\ => 12^{2} -4.9.4 \\ 144-144=0 \\ \sqrt{0} =0 \\ \\ -12+ 0/18= \frac{-12}{18} = \frac{-2}{3} \\ \\ That`s\: enough=>x= \frac{-2}{3} \\ \\ \framebox[1.1\width]{Good Luck!} \par[/tex]