\(\dfrac{4x-18}{\left(x-3\right)\left(x+3\right)}=-4\)
\(\Leftrightarrow\dfrac{4x-18}{x^2-9}=-4\)
\(\Leftrightarrow4x-18=-4x^2+36\)
\(\Leftrightarrow4x^2+4x-54=0\)
\(\Leftrightarrow x^2+x-\dfrac{27}{2}=0\)
\(\Leftrightarrow\left(x+\dfrac{1}{2}\right)^2=\dfrac{55}{4}\)
\(\Leftrightarrow x=\dfrac{-1\pm\sqrt{55}}{2}\)
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