Exercício Resolvido de Inequações
d)
\( 9x^{2}-12x+4<0 \)
\[
\begin{gathered}
9x^{2}-12x+4=0\\[5pt]
\Delta=b^{2}-4ac=(-12)^{2}-4.9.4=144-144=0\\[5pt]
t=\frac{-b\pm\sqrt{\Delta \;}}{2a}=\frac{-(-12)\pm\sqrt{0\;}}{2.9}=\frac{12}{18}\\[5pt]
x=\frac{2}{3}
\end{gathered}
\]
\[ \bbox[#FFCCCC,10px]
{V=\emptyset}
\]