Đáp án:
$\left[ \begin{array}{l}
\left\{ \begin{array}{l}
{R_1} = 30\Omega \\
{R_2} = 10\Omega
\end{array} \right.\\
\left\{ \begin{array}{l}
{R_1} = 10\Omega \\
{R_2} = 30\Omega
\end{array} \right.
\end{array} \right.$
Giải thích các bước giải:
Ta có:
$\begin{array}{l}
{R_1} + {R_2} = \dfrac{U}{I} = \dfrac{{12}}{{0,3}} = 40\\
\Leftrightarrow \dfrac{{{R_1}.{R_2}}}{{{R_1} + {R_2}}} = \dfrac{U}{{I'}} = \dfrac{{12}}{{1,6}} = 7,5\\
\Leftrightarrow \dfrac{{{R_1}.{R_2}}}{{40}} = 7,5 \Rightarrow {R_1}.{R_2} = 300\\
\Leftrightarrow {R_1}\left( {40 - {R_1}} \right) = 300\\
\Leftrightarrow - {R_1}^2 + 40{R_1} - 300 = 0\\
\Leftrightarrow \left[ \begin{array}{l}
\left\{ \begin{array}{l}
{R_1} = 30\Omega \\
{R_2} = 40 - 30 = 10\Omega
\end{array} \right.\\
\left\{ \begin{array}{l}
{R_1} = 10\Omega \\
{R_2} = 40 - 10 = 30\Omega
\end{array} \right.
\end{array} \right.
\end{array}$
