2 câu tương tự nhau nên t làm 1 câu thôi
\(\left(4x-3\right).\left(4x+3\right)-\left(2x-3\right)^2=-18\)
\(\Leftrightarrow16x^2-9-4x^2+12x-9+18=0\)
\(\Leftrightarrow12x^2+12x=0\)
\(\Leftrightarrow12x.\left(x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}12x=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)
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