Question

f(x)=2x^2+3x+1=0

Answer 1

\(f\left(x\right)=2x^2+3x+1=0\)

\(\Leftrightarrow2x^2+2x+x+1=0\)

\(\Leftrightarrow2x\left(x+1\right)+\left(x+1\right)=0\)

\(\Leftrightarrow\left(2x+1\right)\left(x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+1=0\\x+1=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=-1\end{matrix}\right.\)

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Answer 2

Ta có: \(2x^2+3x+1=0\)

\(\Leftrightarrow\left(x+1\right)\left(2x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=-\dfrac{1}{2}\end{matrix}\right.\)