Đáp án:
v1 = 45km/h v2 = 75km/h
Giải thích các bước giải:
$\begin{array}{l}
\Delta {s_1} = s - {s_1} - {s_2}\\
\Leftrightarrow 40 = 60 - {v_1}.\dfrac{1}{6} - {v_2}.\dfrac{1}{6}\\
\Leftrightarrow 20 = \dfrac{1}{6}\left( {{v_1} + {v_2}} \right)\\
\Leftrightarrow {v_1} + {v_2} = 120\left( 1 \right)\\
\Delta {s_2} = s - {s_1} + {s_2}\\
\Leftrightarrow 80 = 60 - {v_1}\dfrac{2}{3} + {v_2}\dfrac{2}{3}\\
\Leftrightarrow 20 = \dfrac{2}{3}\left( {{v_2} - {v_1}} \right)\\
\Leftrightarrow {v_2} - {v_1} = 30km/h\left( 2 \right)\\
\left( 1 \right),\left( 2 \right) \Rightarrow \left\{ \begin{array}{l}
{v_1} = 45km/h\\
{v_2} = 75km/h
\end{array} \right.
\end{array}$