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\begin{document}
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\begin{center}
\section*{\textcolor{red}{Exercices de développements}}

\end{center}




\section*{\textcolor{red}{Solutions}}

\subsection{}

\begin{solution}
Pour tout $x$, $f(x)=(2x+3)(4x+5)=8x^2+22x+15$
\end{solution}

\begin{solution}
Pour tout $x$, $f(x)=(3x-1) (2x+3)=6x^2+7x-3$
\end{solution}

\begin{solution}
Pour tout $x$, $f(x)=80 x^2-82 x-9$.
\end{solution}

\begin{solution}
Pour tout $x$, $f(x)=-10 x^2-86 x-48$.
\end{solution}

\begin{solution}
Pour tout $x$, $f(x)=-9 x^2+17 x+2$.
\end{solution}

\begin{solution}
Pour tout $x$, $f(x)=70 x^2+57 x+5$.
\end{solution}

\begin{solution}
Pour tout $x$, $f(x)=27 x^2+24 x-16$.
\end{solution}

\subsection{}
\begin{solution}
$(x-1) (x+1)=x^2-1$.
\end{solution}

\begin{solution}
$(9 x+5)^2=81 x^2+90 x+25$.
\end{solution}

\begin{solution}
$(5 x-4)^2=25 x^2-40 x+16$.
\end{solution}

\begin{solution}
$(-6 x-4) (4-6 x)=36 x^2-16$.
\end{solution}

\begin{solution}
$(4-x)^2=x^2-8 x+16$.
\end{solution}

\begin{solution}
$(-4 x-2)^2=16 x^2+16 x+4$.
\end{solution}

\begin{solution}
$(-7 x-5) (5-7 x)=49 x^2-25$.
\end{solution}



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