\(\frac{1}{4x^2-12x+9}-\frac{3}{9-4x^2}=\frac{4}{4x^2+12x+9}\)
\(\Leftrightarrow\frac{-1}{\left(3-2x\right)^2}-\frac{3}{\left(3-2x\right)\left(3+2x\right)}=\frac{4}{\left(2x+3\right)^2}\)
\(\Leftrightarrow-4x^2-12x-9-27+12x^2-16x^2+48x-36=0\)
\(\Leftrightarrow-8x^2+36x-72=0\)
Rút -4 ra ngoài \(\Leftrightarrow2x^2-9x+18=0\)
\(\Leftrightarrow\left(2x-3\right)\left(x-6\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}2x-3=0\\x-6=0\end{cases}}\)\(\Leftrightarrow\orbr{\begin{cases}2x=3\\x=6\end{cases}}\)\(\Leftrightarrow\orbr{\begin{cases}x=\frac{3}{2}\\x=6\end{cases}\left(tmđk\right)}\)
