\(a,\left(2x-1\right)^2-\left(4x+1\right)\left(x-2\right)=9\\ \Leftrightarrow4x^2-4x+1-\left(4x^2-8x+x-2\right)=9\\ \Leftrightarrow4x^2-4x+1-4x^2+8x-x+2=9\\ \Leftrightarrow3x+3=9\\ \Leftrightarrow3x=6\\ \Leftrightarrow x=2\)
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Hình như b sai đề, sửa tí nhé
\(b,2x\left(x-1\right)-5x+5=0\\ \Leftrightarrow2x\left(x-1\right)-5\left(x-1\right)=0\\ \Leftrightarrow\left(x-1\right)\left(2x-5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x-1=0\\2x-5=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=\frac{5}{2}\end{matrix}\right.\)
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