Đáp án:
\(\begin{array}{l}
{R_1} = 60\Omega \\
{R_2} = 40\Omega
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
- {R_1}nt{R_2}\\
R = \dfrac{U}{I} = \dfrac{{120}}{{1,2}} = 100\Omega \\
\Rightarrow {R_1} + {R_2} = 100\Omega \\
\Rightarrow {R_2} = 100 - {R_1}\\
- {R_1}//{R_2}\\
R' = \dfrac{U}{{I'}} = \dfrac{{120}}{5} = 24\Omega \\
\Rightarrow \dfrac{{{R_1}{R_2}}}{{{R_1} + {R_2}}} = 24\\
\Rightarrow \dfrac{{{R_1}(100 - {R_1})}}{{100}} = 24\\
\Rightarrow {R_1}^2 - 100{R_1} + 2400 = 0\\
\Rightarrow \left\{ \begin{array}{l}
{R_1} = 60\Omega \\
{R_2} = 40\Omega
\end{array} \right.
\end{array}\)