12045中１・正の数と負の数・計算問題・乗法5
banno計算問題 》乗法⑤
次の式を，累乗の指数を使って表しなさい。
(1) $\;\;5 \times 5$
(2) $\;\;(\,-2\,) \times (\,-2\,) \times (\,-2\,)$
(3) $\;\;1.5 \times 1.5 \times 1.5 \times 1.5$
(4) $\;\;\dfrac{2}{\,5\,} \times \dfrac{2}{\,5\,}\times \dfrac{2}{\,5\,}$
(5) $\;\;-(\,10 \times 10 \times 10 \times 10\,)$
(6) $\;\;\Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr) \times \Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr) \times \Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr)$
解答・解説
$\;\;\begin{eqnarray}(1)\quad\;\;5 \times 5\end{eqnarray}\;\;$
$\qquad\begin{eqnarray}&=&5^{2}\end{eqnarray}\;\;$
答$5^{2}$
$\;\;\begin{eqnarray}(2)\quad\;\;(\,-2\,) \times (\,-2\,) \times (\,-2\,)\end{eqnarray}\;\;$
$\qquad\begin{eqnarray}&=&(\,-2\,)^{3}\end{eqnarray}\;\;$
答$(\,-2\,)^{3}$
$\;\;\begin{eqnarray}(3)\quad\;\;1.5 \times 1.5 \times 1.5 \times 1.5\end{eqnarray}\;\;$
$\qquad\begin{eqnarray}&=&1.5^{4}\end{eqnarray}\;\;$
答$1.5^{4}$
$\;\;\begin{eqnarray}(4)\quad\;\;\dfrac{2}{\,5\,} \times \dfrac{2}{\,5\,}\times \dfrac{2}{\,5\,}\end{eqnarray}\;\;$
$\qquad\begin{eqnarray}&=&\Bigl(\,\dfrac{2}{\,5\,}\,\Bigr)^{3}\end{eqnarray}\;\;$
答$\Bigl(\,\dfrac{2}{\,5\,}\,\Bigr)^{3}$
$\;\;\begin{eqnarray}(5)\quad\;\;-(\,10 \times 10 \times 10 \times 10\,)\end{eqnarray}\;\;$
$\qquad\begin{eqnarray}&=&-10^{4}\end{eqnarray}\;\;$
答$-\,10^{4}$
$\;\;\begin{eqnarray}(6)\quad\;\;\Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr) \times \Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr) \times \Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr)\end{eqnarray}\;\;$
$\qquad\begin{eqnarray}&=&\Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr)^{3}\end{eqnarray}\;\;$
答$\Bigl(\,-\dfrac{3}{\;7\;}\,\Bigr)^{3}$
