Exercice 21 :
↓ Enoncé :
- \( = 7 + 2 \times (8 - 3) \)
- \( = (15 - 5) \times (12 \div 3) \)
- \( = 40 \div (5 \times 2) + 9 \)
- \( = 3 \times [8 + (12 \div 4)] \)
↓ Solution :
- \(
\begin{align}
7 + 2 \times (8 - 3) &= 7 + 2 \times 5 \\
&= 7 + 10 \\
&= 17
\end{align}
\)
- \(
\begin{align}
(15 - 5) \times (12 \div 3) &= 10 \times 4 \\
&= 40
\end{align}
\)
- \(
\begin{align}
40 \div (5 \times 2) + 9 &= 40 \div 10 + 9 \\
&= 4 + 9 \\
&= 13
\end{align}
\)
- \(
\begin{align}
3 \times [8 + (12 \div 4)] &= 3 \times [8 + 3] \\
&= 3 \times 11 \\
&= 33
\end{align}
\)