# exo27.tex

%@P:exocorcp
%@Auteur: François Meria
%@Dif:2
Calculer les expressions suivantes, en écrivant les étapes intermédiaires
et en respectant les règles de priorité :
\begin{multicols}{3}
\begin{description}
\item [$\diamond$] $A = 7\times (6+4)$
\item [$\diamond$] $B = 28-3\times 6$
\item [$\diamond$] $C = (5+2)\times (9-7)$
\item [$\diamond$] $D = (13-7)\div 2$
\item [$\diamond$] $E = 10-[7-(3+2)]$
\item [$\diamond$] $F = 1+(9 + 5 \times 7) \div 4$
\end{description}
\end{multicols}
%@Correction:
\begin{multicols}{3}

$\begin{array}{rl} A = & 7\times (6+4)\\ = & 7\times 10\\ = & 70\\ \end{array}$

$\begin{array}{rl} B = & 28-3\times 6\\ = & 28-18\\ = & 10\\ \end{array}$

$\begin{array}{rl} C = & (5+2)\times (9-7)\\ = & 7\times 2\\ = & 14\\ \end{array}$

$\begin{array}{rl} D = & (13-7)\div 2\\ = & 6 \div 2\\ = & 3\\ \end{array}$

$\begin{array}{rl} E = & 10-[7-(3+2)]\\ = & 10-[7-5]\\ = & 10-2\\ = & 8\\ \end{array}$

$\begin{array}{rl} F = & 1+(9 + 5 \times 7) \div 4 \\ = & 1+(9+35) \div 4\\ = & 1+44\div 4\\ = & 1+11\\ = & 12\\ \end{array}$
\end{multicols}