a) = (x -1). (x + 1)

b) \(=\left(x+3\right)^2\)

c) \(=\left(2x\right)^2-3^2=\left(2x-3\right)\left(2x+3\right)\)

d) \(=\left(4x\right)^2-2.4x.1+1=\left(4x-1\right)^2\)

\(=x^3-3^3=x^3-27\)

\(=\left(x+1\right)^2\)

\(\left\{{}\begin{matrix}x\ne-\dfrac{5}{3}\\-\dfrac{2}{3x+5}>0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ne-\dfrac{5}{3}\\3x+5< 0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ne-\dfrac{5}{3}\\x< -\dfrac{5}{3}\end{matrix}\right.\Leftrightarrow x< -\dfrac{5}{3}\)

Chữ đẹp vc :)))

Aaa, xin lũi anh e nhầm :((

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