21052中２・式の計算・計算問題・単項式の除法2

$\begin{eqnarray}(1)\quad\;\;x^{2}y \div xy\end{eqnarray}\;\;$

$\begin{eqnarray}\quad\;\;&=&\dfrac{\, \color{red}\cancelto{1}{\color{black}x} \color{black}\times x \times \color{aqua}\cancelto{1}{\color{black}y}\,}{\,\color{red}\cancelto{1}{\color{black}x}\color{black}\times \color{aqua}\cancelto{1}{\color{black}y}\,}\\[6pt]&=&x\end{eqnarray}\;\;$

答$x$

$\begin{eqnarray}(2)\quad\;\;(\,-3a^{2}b^{2}\,) \div ab^{2}\end{eqnarray}\;\;$

$\begin{eqnarray}\quad\;\;&=&-\dfrac{\,3 \times \color{red}\cancelto{1}{\color{black}a} \color{black}\times a \times \color{aqua}\cancelto{1}{\color{black}b} \color{black}\times \color{aqua}\cancelto{1}{\color{black}b}\,}{\,\color{red}\cancelto{1}{\color{black}a} \color{black}\times \color{aqua}\cancelto{1}{\color{black}b} \color{black}\times \color{aqua}\cancelto{1}{\color{black}b}\,}\\[6pt]&=&-3a\end{eqnarray}\;\;$

答$-\,3a$

$\begin{eqnarray}(3)\quad\;\;16x^{3}y^{2} \div (\,-4x^{2}y\,)\end{eqnarray}\;\;$

$\begin{eqnarray}\quad\;\;&=&-\dfrac{\,\color{silver}\cancelto{4}{\color{black}16} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times x \times \color{aqua}\cancelto{1}{\color{black}y} \color{black}\times y\,}{\,\color{silver}\cancelto{1}{\color{black}4} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{aqua}\cancelto{1}{\color{black}y}\,}\\[6pt]&=&-4xy\end{eqnarray}\;\;$

答$-\,4xy$

$\begin{eqnarray}(4)\quad\;\;(\,-28a^{2}b^{3}\,) \div 7a^{2}b\end{eqnarray}\;\;$

$\begin{eqnarray}\quad\;\;&=&-\dfrac{\,\color{silver}\cancelto{4}{\color{black}28} \color{black}\times \color{red}\cancelto{1}{\color{black}a} \color{black}\times \color{red}\cancelto{1}{\color{black}a} \color{black}\times \color{aqua}\cancelto{1}{\color{black}b} \color{black}\times b \color{black}\times b\,}{\,\color{silver}\cancelto{1}{\color{black}7} \color{black}\times \color{red}\cancelto{1}{\color{black}a} \color{black}\times \color{red}\cancelto{1}{\color{black}a} \color{black}\times \color{aqua}\cancelto{1}{\color{black}b}\,}\\[6pt]&=&-4b^{2}\end{eqnarray}\;\;$

答$-\,4b^{2}$

$\begin{eqnarray}(5)\quad\;\;(\,-5x^{4}y^{2}\,) \div (\,-3x^{3}y^{2}\,)\end{eqnarray}\;\;$

$\begin{eqnarray}\quad\;\;&=&+\dfrac{\,5\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times x \times \color{aqua}\cancelto{1}{\color{black}y} \color{black}\times \color{aqua}\cancelto{1}{\color{black}y}\,}{\,3 \times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{red}\cancelto{1}{\color{black}x} \color{black}\times \color{aqua}\cancelto{1}{\color{black}y} \color{black}\times \color{aqua}\cancelto{1}{\color{black}y}\,}\\[6pt]&=&\dfrac{5}{\;3\;}x\end{eqnarray}\;\;$

答$\dfrac{5}{\;3\;}x$