Question

trình bay đầy đủ nha

 

Answer 1

a) \(\Leftrightarrow\left(x+5\right)^2=4^2\)
    \(\Leftrightarrow x+5=4\)
    \(\Leftrightarrow x=-1\)
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b) \(\Leftrightarrow2\left(x-4\right)+x\left(x-4\right)=0\)
    \(\Leftrightarrow\left(x-4\right)\left(2+x\right)=0\)
    \(\Leftrightarrow\left[{}\begin{matrix}x-4=0\\2+x=0\end{matrix}\right.\)
    \(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-2\end{matrix}\right.\)
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